Re: [U-Boot] [PATCH v2 3/5] dm: ns16550: Don't map_physmem for I/O ports

[Paul Burton]

On Sat, May 21, 2016 at 06:50:37PM +0200, Daniel Schwierzeck wrote:
> are you going to send a v4 of this patch? I can also do this if you
> like. Then I could apply all other v3 patches of this series.

Hi Daniel,

I'm happy with either of those options. If you'd prefer me to submit a
v4 let me know, but I'd be happy with you replacing patch 3/5.

Thanks,
Paul
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Re: [U-Boot] [PATCH v2 3/5] dm: ns16550: Don't map_physmem for I/O ports

[Daniel Schwierzeck]

Hi Paul,

Am 18.05.2016 um 16:52 schrieb Simon Glass:
>>>
>>> Are you sure systems rely on using I/O ports with map_physmem? The only
>>> other systems that define CONFIG_SYS_NS16550_PORT_MAPPED are x86 ones,
>>> in include/configs/x86-common.h, and so far as I can tell they don't use
>>> device model which suggests this code has simply been untested before. I
>>> don't see why you would use map_physmem on an I/O port address that is
>>> then going to be passed to inb/outb & I think the code here is simply
>>> wrong to do so.
>>
>> the current code looks wrong. serial_in_shift() is expanded to inb()
>> in case of CONFIG_SYS_NS16550_PORT_MAPPED and to
>> in_le32()/in_be32()/readl()/readb() otherwise. Only in the latter case
>> a map_physmem() is required and should be done in serial_in_shift()
>> itself or preferrably only once in
>> ns16550_serial_ofdata_to_platdata().
>>
>> I think the correct approach would be the following:
>
> This is better I think. But how about adding a device tree binding to
> select I/O access? In principle each device might have its own
> settings.

 Note that's what I worked towards last time I had a crack at this, but
 it just expanded into an attempt to tackle the mess that is ns16550.c &
 rather lost sight of the original goal of making Malta work.

 https://patchwork.ozlabs.org/patch/575643/
 https://patchwork.ozlabs.org/patch/577194/
>>>
>>> Yes it is tricky. What do you think about the suggestions above?
>>
>> for now we should only fix the broken port-based I/O. Additional DT
>> bindings could be added later. I'd like to merge the DM support on MIPS
>> Malta in this merge window ;)
> 
> In that case your patch of moving it to ofdata_to_platdata() looks OK to me.

are you going to send a v4 of this patch? I can also do this if you
like. Then I could apply all other v3 patches of this series.

-- 
- Daniel



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Re: [U-Boot] [PATCH v2 3/5] dm: ns16550: Don't map_physmem for I/O ports

[Simon Glass]

Hi Daniel,

On 18 May 2016 at 04:04, Daniel Schwierzeck
 wrote:
>
>
> Am 17.05.2016 um 18:00 schrieb Simon Glass:
>> Hi Paul,
>>
>> On 17 May 2016 at 09:58, Paul Burton  wrote:
>>> On Tue, May 17, 2016 at 09:54:21AM -0600, Simon Glass wrote:
 diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c
 index 28da9dd..e58e6aa 100644
 --- a/drivers/serial/ns16550.c
 +++ b/drivers/serial/ns16550.c
 @@ -100,7 +100,11 @@ static void ns16550_writeb(NS16550_t port, int 
 offset, int value)
 unsigned char *addr;

 offset *= 1 << plat->reg_shift;
 +#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
 +   addr = (unsigned char *)plat->base + offset;
 +#else
 addr = map_physmem(plat->base, 0, MAP_NOCACHE) + offset;
 +#endif
>>>
>>> Please don't add CONFIG #ifdefs in these functions. Perhaps it needs
>>> to be another parameter? Possibly a flag. But with driver-model we
>>> need to be able to support both options in the core code.
>>
>> Hi Simon,
>>
>> Are you sure systems rely on using I/O ports with map_physmem? The only
>> other systems that define CONFIG_SYS_NS16550_PORT_MAPPED are x86 ones,
>> in include/configs/x86-common.h, and so far as I can tell they don't use
>> device model which suggests this code has simply been untested before. I
>> don't see why you would use map_physmem on an I/O port address that is
>> then going to be passed to inb/outb & I think the code here is simply
>> wrong to do so.
>
> the current code looks wrong. serial_in_shift() is expanded to inb()
> in case of CONFIG_SYS_NS16550_PORT_MAPPED and to
> in_le32()/in_be32()/readl()/readb() otherwise. Only in the latter case
> a map_physmem() is required and should be done in serial_in_shift()
> itself or preferrably only once in
> ns16550_serial_ofdata_to_platdata().
>
> I think the correct approach would be the following:

 This is better I think. But how about adding a device tree binding to
 select I/O access? In principle each device might have its own
 settings.
>>>
>>> Note that's what I worked towards last time I had a crack at this, but
>>> it just expanded into an attempt to tackle the mess that is ns16550.c &
>>> rather lost sight of the original goal of making Malta work.
>>>
>>> https://patchwork.ozlabs.org/patch/575643/
>>> https://patchwork.ozlabs.org/patch/577194/
>>
>> Yes it is tricky. What do you think about the suggestions above?
>
> for now we should only fix the broken port-based I/O. Additional DT
> bindings could be added later. I'd like to merge the DM support on MIPS
> Malta in this merge window ;)

In that case your patch of moving it to ofdata_to_platdata() looks OK to me.

Regards,
Simon
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Re: [U-Boot] [PATCH v2 3/5] dm: ns16550: Don't map_physmem for I/O ports

[Daniel Schwierzeck]

Am 17.05.2016 um 18:00 schrieb Simon Glass:
> Hi Paul,
> 
> On 17 May 2016 at 09:58, Paul Burton  wrote:
>> On Tue, May 17, 2016 at 09:54:21AM -0600, Simon Glass wrote:
>>> diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c
>>> index 28da9dd..e58e6aa 100644
>>> --- a/drivers/serial/ns16550.c
>>> +++ b/drivers/serial/ns16550.c
>>> @@ -100,7 +100,11 @@ static void ns16550_writeb(NS16550_t port, int 
>>> offset, int value)
>>> unsigned char *addr;
>>>
>>> offset *= 1 << plat->reg_shift;
>>> +#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
>>> +   addr = (unsigned char *)plat->base + offset;
>>> +#else
>>> addr = map_physmem(plat->base, 0, MAP_NOCACHE) + offset;
>>> +#endif
>>
>> Please don't add CONFIG #ifdefs in these functions. Perhaps it needs
>> to be another parameter? Possibly a flag. But with driver-model we
>> need to be able to support both options in the core code.
>
> Hi Simon,
>
> Are you sure systems rely on using I/O ports with map_physmem? The only
> other systems that define CONFIG_SYS_NS16550_PORT_MAPPED are x86 ones,
> in include/configs/x86-common.h, and so far as I can tell they don't use
> device model which suggests this code has simply been untested before. I
> don't see why you would use map_physmem on an I/O port address that is
> then going to be passed to inb/outb & I think the code here is simply
> wrong to do so.

 the current code looks wrong. serial_in_shift() is expanded to inb()
 in case of CONFIG_SYS_NS16550_PORT_MAPPED and to
 in_le32()/in_be32()/readl()/readb() otherwise. Only in the latter case
 a map_physmem() is required and should be done in serial_in_shift()
 itself or preferrably only once in
 ns16550_serial_ofdata_to_platdata().

 I think the correct approach would be the following:
>>>
>>> This is better I think. But how about adding a device tree binding to
>>> select I/O access? In principle each device might have its own
>>> settings.
>>
>> Note that's what I worked towards last time I had a crack at this, but
>> it just expanded into an attempt to tackle the mess that is ns16550.c &
>> rather lost sight of the original goal of making Malta work.
>>
>> https://patchwork.ozlabs.org/patch/575643/
>> https://patchwork.ozlabs.org/patch/577194/
> 
> Yes it is tricky. What do you think about the suggestions above?

for now we should only fix the broken port-based I/O. Additional DT
bindings could be added later. I'd like to merge the DM support on MIPS
Malta in this merge window ;)

-- 
- Daniel



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Re: [U-Boot] [PATCH v2 3/5] dm: ns16550: Don't map_physmem for I/O ports

[Simon Glass]

Hi Paul,

On 17 May 2016 at 09:58, Paul Burton  wrote:
> On Tue, May 17, 2016 at 09:54:21AM -0600, Simon Glass wrote:
>> > >> > diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c
>> > >> > index 28da9dd..e58e6aa 100644
>> > >> > --- a/drivers/serial/ns16550.c
>> > >> > +++ b/drivers/serial/ns16550.c
>> > >> > @@ -100,7 +100,11 @@ static void ns16550_writeb(NS16550_t port, int 
>> > >> > offset, int value)
>> > >> > unsigned char *addr;
>> > >> >
>> > >> > offset *= 1 << plat->reg_shift;
>> > >> > +#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
>> > >> > +   addr = (unsigned char *)plat->base + offset;
>> > >> > +#else
>> > >> > addr = map_physmem(plat->base, 0, MAP_NOCACHE) + offset;
>> > >> > +#endif
>> > >>
>> > >> Please don't add CONFIG #ifdefs in these functions. Perhaps it needs
>> > >> to be another parameter? Possibly a flag. But with driver-model we
>> > >> need to be able to support both options in the core code.
>> > >
>> > > Hi Simon,
>> > >
>> > > Are you sure systems rely on using I/O ports with map_physmem? The only
>> > > other systems that define CONFIG_SYS_NS16550_PORT_MAPPED are x86 ones,
>> > > in include/configs/x86-common.h, and so far as I can tell they don't use
>> > > device model which suggests this code has simply been untested before. I
>> > > don't see why you would use map_physmem on an I/O port address that is
>> > > then going to be passed to inb/outb & I think the code here is simply
>> > > wrong to do so.
>> >
>> > the current code looks wrong. serial_in_shift() is expanded to inb()
>> > in case of CONFIG_SYS_NS16550_PORT_MAPPED and to
>> > in_le32()/in_be32()/readl()/readb() otherwise. Only in the latter case
>> > a map_physmem() is required and should be done in serial_in_shift()
>> > itself or preferrably only once in
>> > ns16550_serial_ofdata_to_platdata().
>> >
>> > I think the correct approach would be the following:
>>
>> This is better I think. But how about adding a device tree binding to
>> select I/O access? In principle each device might have its own
>> settings.
>
> Note that's what I worked towards last time I had a crack at this, but
> it just expanded into an attempt to tackle the mess that is ns16550.c &
> rather lost sight of the original goal of making Malta work.
>
> https://patchwork.ozlabs.org/patch/575643/
> https://patchwork.ozlabs.org/patch/577194/

Yes it is tricky. What do you think about the suggestions above?

Regards,
Simon
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Re: [U-Boot] [PATCH v2 3/5] dm: ns16550: Don't map_physmem for I/O ports

[Paul Burton]

On Tue, May 17, 2016 at 09:54:21AM -0600, Simon Glass wrote:
> > >> > diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c
> > >> > index 28da9dd..e58e6aa 100644
> > >> > --- a/drivers/serial/ns16550.c
> > >> > +++ b/drivers/serial/ns16550.c
> > >> > @@ -100,7 +100,11 @@ static void ns16550_writeb(NS16550_t port, int 
> > >> > offset, int value)
> > >> > unsigned char *addr;
> > >> >
> > >> > offset *= 1 << plat->reg_shift;
> > >> > +#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
> > >> > +   addr = (unsigned char *)plat->base + offset;
> > >> > +#else
> > >> > addr = map_physmem(plat->base, 0, MAP_NOCACHE) + offset;
> > >> > +#endif
> > >>
> > >> Please don't add CONFIG #ifdefs in these functions. Perhaps it needs
> > >> to be another parameter? Possibly a flag. But with driver-model we
> > >> need to be able to support both options in the core code.
> > >
> > > Hi Simon,
> > >
> > > Are you sure systems rely on using I/O ports with map_physmem? The only
> > > other systems that define CONFIG_SYS_NS16550_PORT_MAPPED are x86 ones,
> > > in include/configs/x86-common.h, and so far as I can tell they don't use
> > > device model which suggests this code has simply been untested before. I
> > > don't see why you would use map_physmem on an I/O port address that is
> > > then going to be passed to inb/outb & I think the code here is simply
> > > wrong to do so.
> >
> > the current code looks wrong. serial_in_shift() is expanded to inb()
> > in case of CONFIG_SYS_NS16550_PORT_MAPPED and to
> > in_le32()/in_be32()/readl()/readb() otherwise. Only in the latter case
> > a map_physmem() is required and should be done in serial_in_shift()
> > itself or preferrably only once in
> > ns16550_serial_ofdata_to_platdata().
> >
> > I think the correct approach would be the following:
> 
> This is better I think. But how about adding a device tree binding to
> select I/O access? In principle each device might have its own
> settings.

Note that's what I worked towards last time I had a crack at this, but
it just expanded into an attempt to tackle the mess that is ns16550.c &
rather lost sight of the original goal of making Malta work.

https://patchwork.ozlabs.org/patch/575643/
https://patchwork.ozlabs.org/patch/577194/

Thanks,
Paul
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Re: [U-Boot] [PATCH v2 3/5] dm: ns16550: Don't map_physmem for I/O ports

[Simon Glass]

Hi Daniel,

On 17 May 2016 at 09:51, Daniel Schwierzeck
 wrote:
>
> 2016-05-17 14:48 GMT+02:00 Paul Burton :
> > On Tue, May 17, 2016 at 06:11:22AM -0600, Simon Glass wrote:
> >> Hi Paul,
> >>
> >> On 16 May 2016 at 11:44, Paul Burton  wrote:
> >> > If the UART is to be accessed using I/O port accessors (inb & outb) then
> >> > using map_physmem doesn't make sense, since it operates in a different
> >> > memory space. Remove the call to map_physmem when
> >> > CONFIG_SYS_NS16550_PORT_MAPPED is defined, allowing I/O port addresses
> >> > to not be mangled by the incorrect mapping.
> >> >
> >> > Signed-off-by: Paul Burton 
> >> > ---
> >> >
> >> > Changes in v2:
> >> > - New patch, part of a simplified approach tackling only a single Malta 
> >> > UART.
> >> >
> >> >  drivers/serial/ns16550.c | 8 
> >> >  1 file changed, 8 insertions(+)
> >> >
> >> > diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c
> >> > index 28da9dd..e58e6aa 100644
> >> > --- a/drivers/serial/ns16550.c
> >> > +++ b/drivers/serial/ns16550.c
> >> > @@ -100,7 +100,11 @@ static void ns16550_writeb(NS16550_t port, int 
> >> > offset, int value)
> >> > unsigned char *addr;
> >> >
> >> > offset *= 1 << plat->reg_shift;
> >> > +#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
> >> > +   addr = (unsigned char *)plat->base + offset;
> >> > +#else
> >> > addr = map_physmem(plat->base, 0, MAP_NOCACHE) + offset;
> >> > +#endif
> >>
> >> Please don't add CONFIG #ifdefs in these functions. Perhaps it needs
> >> to be another parameter? Possibly a flag. But with driver-model we
> >> need to be able to support both options in the core code.
> >
> > Hi Simon,
> >
> > Are you sure systems rely on using I/O ports with map_physmem? The only
> > other systems that define CONFIG_SYS_NS16550_PORT_MAPPED are x86 ones,
> > in include/configs/x86-common.h, and so far as I can tell they don't use
> > device model which suggests this code has simply been untested before. I
> > don't see why you would use map_physmem on an I/O port address that is
> > then going to be passed to inb/outb & I think the code here is simply
> > wrong to do so.
>
> the current code looks wrong. serial_in_shift() is expanded to inb()
> in case of CONFIG_SYS_NS16550_PORT_MAPPED and to
> in_le32()/in_be32()/readl()/readb() otherwise. Only in the latter case
> a map_physmem() is required and should be done in serial_in_shift()
> itself or preferrably only once in
> ns16550_serial_ofdata_to_platdata().
>
> I think the correct approach would be the following:

This is better I think. But how about adding a device tree binding to
select I/O access? In principle each device might have its own
settings.

>
> --- a/drivers/serial/ns16550.c
> +++ b/drivers/serial/ns16550.c
> @@ -100,7 +100,8 @@ static void ns16550_writeb(NS16550_t port, int
> offset, int value)
> unsigned char *addr;
>
> offset *= 1 << plat->reg_shift;
> -   addr = map_physmem(plat->base, 0, MAP_NOCACHE) + offset;
> +   addr = plat->base + offset;
> +
> /*
>  * As far as we know it doesn't make sense to support selection of
>  * these options at run-time, so use the existing CONFIG options.
> @@ -114,7 +115,7 @@ static int ns16550_readb(NS16550_t port, int offset)
> unsigned char *addr;
>
> offset *= 1 << plat->reg_shift;
> -   addr = map_physmem(plat->base, 0, MAP_NOCACHE) + offset;
> +   addr = plat->base + offset;
>
> return serial_in_shift(addr + plat->reg_offset, plat->reg_shift);
>  }
> @@ -400,7 +401,12 @@ int ns16550_serial_ofdata_to_platdata(struct udevice 
> *dev)
> if (addr == FDT_ADDR_T_NONE)
> return -EINVAL;
>
> +#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
> plat->base = addr;
> +#else
> +   plat->base = map_physmem(addr, 0, MAP_NOCACHE);
> +#endif
> +
> plat->reg_offset = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
>  "reg-offset", 0);
> plat->reg_shift = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
>
> --
> - Daniel

Regards,
Simon
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Re: [U-Boot] [PATCH v2 3/5] dm: ns16550: Don't map_physmem for I/O ports

[Daniel Schwierzeck]

2016-05-17 14:48 GMT+02:00 Paul Burton :
> On Tue, May 17, 2016 at 06:11:22AM -0600, Simon Glass wrote:
>> Hi Paul,
>>
>> On 16 May 2016 at 11:44, Paul Burton  wrote:
>> > If the UART is to be accessed using I/O port accessors (inb & outb) then
>> > using map_physmem doesn't make sense, since it operates in a different
>> > memory space. Remove the call to map_physmem when
>> > CONFIG_SYS_NS16550_PORT_MAPPED is defined, allowing I/O port addresses
>> > to not be mangled by the incorrect mapping.
>> >
>> > Signed-off-by: Paul Burton 
>> > ---
>> >
>> > Changes in v2:
>> > - New patch, part of a simplified approach tackling only a single Malta 
>> > UART.
>> >
>> >  drivers/serial/ns16550.c | 8 
>> >  1 file changed, 8 insertions(+)
>> >
>> > diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c
>> > index 28da9dd..e58e6aa 100644
>> > --- a/drivers/serial/ns16550.c
>> > +++ b/drivers/serial/ns16550.c
>> > @@ -100,7 +100,11 @@ static void ns16550_writeb(NS16550_t port, int 
>> > offset, int value)
>> > unsigned char *addr;
>> >
>> > offset *= 1 << plat->reg_shift;
>> > +#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
>> > +   addr = (unsigned char *)plat->base + offset;
>> > +#else
>> > addr = map_physmem(plat->base, 0, MAP_NOCACHE) + offset;
>> > +#endif
>>
>> Please don't add CONFIG #ifdefs in these functions. Perhaps it needs
>> to be another parameter? Possibly a flag. But with driver-model we
>> need to be able to support both options in the core code.
>
> Hi Simon,
>
> Are you sure systems rely on using I/O ports with map_physmem? The only
> other systems that define CONFIG_SYS_NS16550_PORT_MAPPED are x86 ones,
> in include/configs/x86-common.h, and so far as I can tell they don't use
> device model which suggests this code has simply been untested before. I
> don't see why you would use map_physmem on an I/O port address that is
> then going to be passed to inb/outb & I think the code here is simply
> wrong to do so.

the current code looks wrong. serial_in_shift() is expanded to inb()
in case of CONFIG_SYS_NS16550_PORT_MAPPED and to
in_le32()/in_be32()/readl()/readb() otherwise. Only in the latter case
a map_physmem() is required and should be done in serial_in_shift()
itself or preferrably only once in
ns16550_serial_ofdata_to_platdata().

I think the correct approach would be the following:

--- a/drivers/serial/ns16550.c
+++ b/drivers/serial/ns16550.c
@@ -100,7 +100,8 @@ static void ns16550_writeb(NS16550_t port, int
offset, int value)
unsigned char *addr;

offset *= 1 << plat->reg_shift;
-   addr = map_physmem(plat->base, 0, MAP_NOCACHE) + offset;
+   addr = plat->base + offset;
+
/*
 * As far as we know it doesn't make sense to support selection of
 * these options at run-time, so use the existing CONFIG options.
@@ -114,7 +115,7 @@ static int ns16550_readb(NS16550_t port, int offset)
unsigned char *addr;

offset *= 1 << plat->reg_shift;
-   addr = map_physmem(plat->base, 0, MAP_NOCACHE) + offset;
+   addr = plat->base + offset;

return serial_in_shift(addr + plat->reg_offset, plat->reg_shift);
 }
@@ -400,7 +401,12 @@ int ns16550_serial_ofdata_to_platdata(struct udevice *dev)
if (addr == FDT_ADDR_T_NONE)
return -EINVAL;

+#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
plat->base = addr;
+#else
+   plat->base = map_physmem(addr, 0, MAP_NOCACHE);
+#endif
+
plat->reg_offset = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
 "reg-offset", 0);
plat->reg_shift = fdtdec_get_int(gd->fdt_blob, dev->of_offset,

-- 
- Daniel
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Re: [U-Boot] [PATCH v2 3/5] dm: ns16550: Don't map_physmem for I/O ports

[Paul Burton]

On Tue, May 17, 2016 at 06:11:22AM -0600, Simon Glass wrote:
> Hi Paul,
> 
> On 16 May 2016 at 11:44, Paul Burton  wrote:
> > If the UART is to be accessed using I/O port accessors (inb & outb) then
> > using map_physmem doesn't make sense, since it operates in a different
> > memory space. Remove the call to map_physmem when
> > CONFIG_SYS_NS16550_PORT_MAPPED is defined, allowing I/O port addresses
> > to not be mangled by the incorrect mapping.
> >
> > Signed-off-by: Paul Burton 
> > ---
> >
> > Changes in v2:
> > - New patch, part of a simplified approach tackling only a single Malta 
> > UART.
> >
> >  drivers/serial/ns16550.c | 8 
> >  1 file changed, 8 insertions(+)
> >
> > diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c
> > index 28da9dd..e58e6aa 100644
> > --- a/drivers/serial/ns16550.c
> > +++ b/drivers/serial/ns16550.c
> > @@ -100,7 +100,11 @@ static void ns16550_writeb(NS16550_t port, int offset, 
> > int value)
> > unsigned char *addr;
> >
> > offset *= 1 << plat->reg_shift;
> > +#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
> > +   addr = (unsigned char *)plat->base + offset;
> > +#else
> > addr = map_physmem(plat->base, 0, MAP_NOCACHE) + offset;
> > +#endif
> 
> Please don't add CONFIG #ifdefs in these functions. Perhaps it needs
> to be another parameter? Possibly a flag. But with driver-model we
> need to be able to support both options in the core code.

Hi Simon,

Are you sure systems rely on using I/O ports with map_physmem? The only
other systems that define CONFIG_SYS_NS16550_PORT_MAPPED are x86 ones,
in include/configs/x86-common.h, and so far as I can tell they don't use
device model which suggests this code has simply been untested before. I
don't see why you would use map_physmem on an I/O port address that is
then going to be passed to inb/outb & I think the code here is simply
wrong to do so.

> This driver is a real mess. I'm hoping we can simplify it once we have
> everything on driver model.

Agreed, that would be wonderful.

Thanks,
Paul
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Re: [U-Boot] [PATCH v2 3/5] dm: ns16550: Don't map_physmem for I/O ports

[Simon Glass]

Hi Paul,

On 16 May 2016 at 11:44, Paul Burton  wrote:
> If the UART is to be accessed using I/O port accessors (inb & outb) then
> using map_physmem doesn't make sense, since it operates in a different
> memory space. Remove the call to map_physmem when
> CONFIG_SYS_NS16550_PORT_MAPPED is defined, allowing I/O port addresses
> to not be mangled by the incorrect mapping.
>
> Signed-off-by: Paul Burton 
> ---
>
> Changes in v2:
> - New patch, part of a simplified approach tackling only a single Malta UART.
>
>  drivers/serial/ns16550.c | 8 
>  1 file changed, 8 insertions(+)
>
> diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c
> index 28da9dd..e58e6aa 100644
> --- a/drivers/serial/ns16550.c
> +++ b/drivers/serial/ns16550.c
> @@ -100,7 +100,11 @@ static void ns16550_writeb(NS16550_t port, int offset, 
> int value)
> unsigned char *addr;
>
> offset *= 1 << plat->reg_shift;
> +#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
> +   addr = (unsigned char *)plat->base + offset;
> +#else
> addr = map_physmem(plat->base, 0, MAP_NOCACHE) + offset;
> +#endif

Please don't add CONFIG #ifdefs in these functions. Perhaps it needs
to be another parameter? Possibly a flag. But with driver-model we
need to be able to support both options in the core code.

This driver is a real mess. I'm hoping we can simplify it once we have
everything on driver model.

> /*
>  * As far as we know it doesn't make sense to support selection of
>  * these options at run-time, so use the existing CONFIG options.
> @@ -114,7 +118,11 @@ static int ns16550_readb(NS16550_t port, int offset)
> unsigned char *addr;
>
> offset *= 1 << plat->reg_shift;
> +#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
> +   addr = (unsigned char *)plat->base + offset;
> +#else
> addr = map_physmem(plat->base, 0, MAP_NOCACHE) + offset;
> +#endif
>
> return serial_in_shift(addr + plat->reg_offset, plat->reg_shift);
>  }
> --
> 2.8.2
>

Regards,
Simon
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Re: [U-Boot] [PATCH v2 3/5] dm: ns16550: Don't map_physmem for I/O ports

[Daniel Schwierzeck]

Am 16.05.2016 um 19:44 schrieb Paul Burton:
> If the UART is to be accessed using I/O port accessors (inb & outb) then
> using map_physmem doesn't make sense, since it operates in a different
> memory space. Remove the call to map_physmem when
> CONFIG_SYS_NS16550_PORT_MAPPED is defined, allowing I/O port addresses
> to not be mangled by the incorrect mapping.
> 
> Signed-off-by: Paul Burton 

Reviewed-by: Daniel Schwierzeck 
Tested-by: Daniel Schwierzeck 

> ---
> 
> Changes in v2:
> - New patch, part of a simplified approach tackling only a single Malta UART.
> 
>  drivers/serial/ns16550.c | 8 
>  1 file changed, 8 insertions(+)
> 
> diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c
> index 28da9dd..e58e6aa 100644
> --- a/drivers/serial/ns16550.c
> +++ b/drivers/serial/ns16550.c
> @@ -100,7 +100,11 @@ static void ns16550_writeb(NS16550_t port, int offset, 
> int value)
>   unsigned char *addr;
>  
>   offset *= 1 << plat->reg_shift;
> +#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
> + addr = (unsigned char *)plat->base + offset;
> +#else
>   addr = map_physmem(plat->base, 0, MAP_NOCACHE) + offset;
> +#endif
>   /*
>* As far as we know it doesn't make sense to support selection of
>* these options at run-time, so use the existing CONFIG options.
> @@ -114,7 +118,11 @@ static int ns16550_readb(NS16550_t port, int offset)
>   unsigned char *addr;
>  
>   offset *= 1 << plat->reg_shift;
> +#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
> + addr = (unsigned char *)plat->base + offset;
> +#else
>   addr = map_physmem(plat->base, 0, MAP_NOCACHE) + offset;
> +#endif
>  
>   return serial_in_shift(addr + plat->reg_offset, plat->reg_shift);
>  }
> 

-- 
- Daniel



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[U-Boot] [PATCH v2 3/5] dm: ns16550: Don't map_physmem for I/O ports

[Paul Burton]

If the UART is to be accessed using I/O port accessors (inb & outb) then
using map_physmem doesn't make sense, since it operates in a different
memory space. Remove the call to map_physmem when
CONFIG_SYS_NS16550_PORT_MAPPED is defined, allowing I/O port addresses
to not be mangled by the incorrect mapping.

Signed-off-by: Paul Burton 
---

Changes in v2:
- New patch, part of a simplified approach tackling only a single Malta UART.

 drivers/serial/ns16550.c | 8 
 1 file changed, 8 insertions(+)

diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c
index 28da9dd..e58e6aa 100644
--- a/drivers/serial/ns16550.c
+++ b/drivers/serial/ns16550.c
@@ -100,7 +100,11 @@ static void ns16550_writeb(NS16550_t port, int offset, int 
value)
unsigned char *addr;
 
offset *= 1 << plat->reg_shift;
+#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
+   addr = (unsigned char *)plat->base + offset;
+#else
addr = map_physmem(plat->base, 0, MAP_NOCACHE) + offset;
+#endif
/*
 * As far as we know it doesn't make sense to support selection of
 * these options at run-time, so use the existing CONFIG options.
@@ -114,7 +118,11 @@ static int ns16550_readb(NS16550_t port, int offset)
unsigned char *addr;
 
offset *= 1 << plat->reg_shift;
+#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
+   addr = (unsigned char *)plat->base + offset;
+#else
addr = map_physmem(plat->base, 0, MAP_NOCACHE) + offset;
+#endif
 
return serial_in_shift(addr + plat->reg_offset, plat->reg_shift);
 }
-- 
2.8.2

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