Re[4]: [RFC] [PATCH] powerpc: Add MSR_DE to MSR_KERNEL
> Abatron Support wrote on 2012/05/30 14:08:26: >> >> >> I have tested this briefly with BDI2000 on P2010(e500) and >> >> it works for me. I don't know if there are any bad side effects, >> >> therfore >> >> this RFC. >> >> > We used to have MSR_DE surrounded by CONFIG_something >> > to ensure it wasn't set under normal operation. IIRC, if MSR_DE >> > is set, you will have problems with software debuggers that >> > utilize the the debugging registers in the chip itself. You only want >> > to force this to be set when using the BDI, not at other times. >> >> This MSR_DE is also of interest and used for software debuggers that >> make use of the debug registers. Only if MSR_DE is set then debug >> interrupts are generated. If a debug event leads to a debug interrupt >> handled by a software debugger or if it leads to a debug halt handled >> by a JTAG tool is selected with DBCR0_EDM / DBCR0_IDM. >> >> The "e500 Core Family Reference Manual" chapter "Chapter 8 >> Debug Support" explains in detail the effect of MSR_DE. > So what is the verdict on this? I don't buy into Dan argument without some > hard data. What I tried to mention is that handling the MSR_DE correct is not only an emulator (JTAG debugger) requirement. Also a software debugger may depend on a correct handled MSR_DE bit. Ruedi ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re[2]: [RFC] [PATCH] powerpc: Add MSR_DE to MSR_KERNEL
>> I have tested this briefly with BDI2000 on P2010(e500) and >> it works for me. I don't know if there are any bad side effects, >> therfore >> this RFC. > We used to have MSR_DE surrounded by CONFIG_something > to ensure it wasn't set under normal operation. IIRC, if MSR_DE > is set, you will have problems with software debuggers that > utilize the the debugging registers in the chip itself. You only want > to force this to be set when using the BDI, not at other times. This MSR_DE is also of interest and used for software debuggers that make use of the debug registers. Only if MSR_DE is set then debug interrupts are generated. If a debug event leads to a debug interrupt handled by a software debugger or if it leads to a debug halt handled by a JTAG tool is selected with DBCR0_EDM / DBCR0_IDM. The "e500 Core Family Reference Manual" chapter "Chapter 8 Debug Support" explains in detail the effect of MSR_DE. Ruedi ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
RE: [patch 1/2] powerpc: Sky CPU: redundant or incorrect tests on unsigned
We don't plan on carrying it forward, so I assume that ripping it out will not affect us. Anything new would be completely new development. -Original Message- From: Benjamin Herrenschmidt [mailto:b...@kernel.crashing.org] Sent: Wednesday, February 03, 2010 9:01 PM To: support Cc: a...@linux-foundation.org; linuxppc-...@ozlabs.org; roel.kl...@gmail.com; ga...@gate.crashing.org; gorcu...@gmail.com; wa...@skycomputers.com Subject: Re: [patch 1/2] powerpc: Sky CPU: redundant or incorrect tests on unsigned On Wed, 2010-02-03 at 20:47 -0500, support wrote: > I doubt we'll be going to be using 7448's any more for future product lines. Hi ! Well, that isn't really the question :-) Is there any interest in ensuring that your current Sky is supported by upstream linux kernels or not ? As I said, the current kernel seems to contain code relative to the Sky CPU that is never enabled and potentially has issue. Are you guys interested in fixing this so that upstream linux supports your existing products, or should we just rip the code out ? Cheers, Ben. > Dave Bushee > Director OEM Sales and Services > SKY Computers Inc. > 27 Industrial Ave. > 978-250-2420 x232 > www.skycomputers.com > > > - Original Message - > From: "Benjamin Herrenschmidt" > To: "support" > Cc: ; ; > ; ; ; > > Sent: Wednesday, February 03, 2010 7:18 PM > Subject: Re: [patch 1/2] powerpc: Sky CPU: redundant or incorrect tests on > unsigned > > > > On Wed, 2010-02-03 at 19:10 -0500, support wrote: > >> The sky cpu is a PPC7448. > >> I'm actually amazed that you guys are still working on a problem for > >> a > >> product that was finished a number of years ago, at the request of > >> someone > >> who hasn't worked here for years. > >> I sorry you, seem to have been wasting your time. > >> I think, but am NOT sure, that our HAA function sets it off. > >> http://www.skycomputers.com/Systems/HAA_HMM.php > >> > >> Still, we have finished the product some time ago, and as far as > >> reported > >> have no problems. > >> Again, I'm sorry you have wasted any time on this, we just recently > >> found > >> these emails. > > > > Well, there seem to be some code in the Linux kernel related to that CPU > > that is either dead or incomplete. So if you guys have no interest in > > it, we might just rip it out completely. > > > > Cheers, > > Ben. > > > > > > ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [patch 1/2] powerpc: Sky CPU: redundant or incorrect tests on unsigned
I doubt we'll be going to be using 7448's any more for future product lines. Dave Bushee Director OEM Sales and Services SKY Computers Inc. 27 Industrial Ave. 978-250-2420 x232 www.skycomputers.com - Original Message - From: "Benjamin Herrenschmidt" To: "support" Cc: ; ; ; ; ; Sent: Wednesday, February 03, 2010 7:18 PM Subject: Re: [patch 1/2] powerpc: Sky CPU: redundant or incorrect tests on unsigned On Wed, 2010-02-03 at 19:10 -0500, support wrote: The sky cpu is a PPC7448. I'm actually amazed that you guys are still working on a problem for a product that was finished a number of years ago, at the request of someone who hasn't worked here for years. I sorry you, seem to have been wasting your time. I think, but am NOT sure, that our HAA function sets it off. http://www.skycomputers.com/Systems/HAA_HMM.php Still, we have finished the product some time ago, and as far as reported have no problems. Again, I'm sorry you have wasted any time on this, we just recently found these emails. Well, there seem to be some code in the Linux kernel related to that CPU that is either dead or incomplete. So if you guys have no interest in it, we might just rip it out completely. Cheers, Ben. ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [patch 1/2] powerpc: Sky CPU: redundant or incorrect tests on unsigned
To All:
The sky cpu is a PPC7448.
I'm actually amazed that you guys are still working on a problem for a
product that was finished a number of years ago, at the request of someone
who hasn't worked here for years.
I sorry you, seem to have been wasting your time.
I think, but am NOT sure, that our HAA function sets it off.
http://www.skycomputers.com/Systems/HAA_HMM.php
Still, we have finished the product some time ago, and as far as reported
have no problems.
Again, I'm sorry you have wasted any time on this, we just recently found
these emails.
Dave Bushee
Director OEM Sales and Services
SKY Computers Inc.
27 Industrial Ave.
978-250-2420 x232
www.skycomputers.com
- Original Message -
From: "Benjamin Herrenschmidt"
To:
Cc: ; ;
; ;
Sent: Wednesday, February 03, 2010 6:21 PM
Subject: Re: [patch 1/2] powerpc: Sky CPU: redundant or incorrect tests on
unsigned
On Tue, 2010-02-02 at 14:40 -0800, a...@linux-foundation.org wrote:
From: Roel Kluin
count is unsigned and cannot be less than 0.
Signed-off-by: Roel Kluin
Acked-by: Cyrill Gorcunov
Cc: Benjamin Herrenschmidt
Cc: Kumar Gala
Cc: Brian Waite
Signed-off-by: Andrew Morton
---
I still have a hard time figuring out what this sky CPU actually is :-)
The whole drivers/misc/hdpuftrs is only built when CONFIG_HDPU_FEATURES
is set and git grep HDPU_FEATURES doesn't show anybody ever setting
it :-)
Is that just dead code ? I'm happy to carry it in powerpc.git if you
wish so but you it would be nice to figure out what's going on there...
Cheers,
Ben.
drivers/misc/hdpuftrs/hdpu_cpustate.c |5 -
1 file changed, 5 deletions(-)
diff -puN
drivers/misc/hdpuftrs/hdpu_cpustate.c~powerpc-sky-cpu-redundant-or-incorrect-tests-on-unsigned
drivers/misc/hdpuftrs/hdpu_cpustate.c
---
a/drivers/misc/hdpuftrs/hdpu_cpustate.c~powerpc-sky-cpu-redundant-or-incorrect-tests-on-unsigned
+++ a/drivers/misc/hdpuftrs/hdpu_cpustate.c
@@ -121,8 +121,6 @@ static ssize_t cpustate_read(struct file
{
unsigned char data;
- if (count < 0)
- return -EFAULT;
if (count == 0)
return 0;
@@ -137,9 +135,6 @@ static ssize_t cpustate_write(struct fil
{
unsigned char data;
- if (count < 0)
- return -EFAULT;
-
if (count == 0)
return 0;
_
___
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