Re: [PATCH] 8250: make probing for TXEN bug a config option
On 2/14/07, Andrew Morton <[EMAIL PROTECTED]> wrote: I think this should be a module option/boot parameter, not a config-time option. NM, the recent changes in 8250 driver eliminated the need for this patch :) Vitaly - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] 8250: make probing for TXEN bug a config option
On Wed, 14 Feb 2007 05:41:53 -0800 "Vitaly Wool" <[EMAIL PROTECTED]> wrote: > On 2/14/07, Andrew Morton <[EMAIL PROTECTED]> wrote: > > On Wed, 14 Feb 2007 11:37:52 +0300 "Vitaly Wool" <[EMAIL PROTECTED]> wrote: > > > Hmm, why? I can't think of a platform where one 8250-compatible UART is > > > problematic and another isn't :) > > > > > > > Is it not possible that the same kernel package can be installed on systems > > which do and don't need this feature? If so, we don't want to force the > > provider of that package to create two packages. > > > > That, plus the chances of the package creator actually knowing about this > > option aren't great. > > > > Generally, if it can be done at runtime it is better to do so, no? > > Okay, yes, I see your point. The same kernel might actually be > supporting several machines. > > But having that as a config option doesn't look too attractive to me. > What about adding a new flag to plat_serial 8250 stuff instead? plat_serial8250_port.flags? Dunno, I'm unfamiliar with it. That seems to be how the share_irqs option is handled. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] 8250: make probing for TXEN bug a config option
On 2/14/07, Andrew Morton <[EMAIL PROTECTED]> wrote: On Wed, 14 Feb 2007 11:37:52 +0300 "Vitaly Wool" <[EMAIL PROTECTED]> wrote: > Hmm, why? I can't think of a platform where one 8250-compatible UART is > problematic and another isn't :) > Is it not possible that the same kernel package can be installed on systems which do and don't need this feature? If so, we don't want to force the provider of that package to create two packages. That, plus the chances of the package creator actually knowing about this option aren't great. Generally, if it can be done at runtime it is better to do so, no? Okay, yes, I see your point. The same kernel might actually be supporting several machines. But having that as a config option doesn't look too attractive to me. What about adding a new flag to plat_serial 8250 stuff instead? Vitaly - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] 8250: make probing for TXEN bug a config option
On Wed, 14 Feb 2007 11:37:52 +0300 "Vitaly Wool" <[EMAIL PROTECTED]> wrote: > On 2/14/07, Andrew Morton <[EMAIL PROTECTED]> wrote: > > > > I think this should be a module option/boot parameter, not a config-time > > option. > > > > > Hmm, why? I can't think of a platform where one 8250-compatible UART is > problematic and another isn't :) > Is it not possible that the same kernel package can be installed on systems which do and don't need this feature? If so, we don't want to force the provider of that package to create two packages. That, plus the chances of the package creator actually knowing about this option aren't great. Generally, if it can be done at runtime it is better to do so, no? - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] 8250: make probing for TXEN bug a config option
On Tue, 26 Dec 2006 19:43:17 +0300 Vitaly Wool <[EMAIL PROTECTED]> wrote:
^^^ Sorry.
> Hello Andrew,
>
> probing for UART_BUG_TXEN in 8250 driver leads to weird effects on some ARM
> boards (pnx4008 for instance). That is, the driver detects UART_BUG_TXEN
> (though it apparently shouldn't) and it leads to symbol loss in console on
> input (i. e. you input 'a' and you get nothing, then you input 'b' and you
> get 'a', then you input 'c' and get 'b' and so on).
>
> The patch below makes this very probing a configuration option turned on by
> default.
>
> drivers/serial/8250.c |5 -
> drivers/serial/Kconfig | 10 ++
> 2 files changed, 14 insertions(+), 1 deletion(-)
>
> Signed-off-by: Vitaly Wool <[EMAIL PROTECTED]>
>
> diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
> index 51f3c73..cf3eb31 100644
> --- a/drivers/serial/8250.c
> +++ b/drivers/serial/8250.c
> @@ -1645,6 +1645,7 @@ static int serial8250_startup(struct uar
>
> serial8250_set_mctrl(&up->port, up->port.mctrl);
>
> +#ifndef CONFIG_SERIAL_8250_DONT_TEST_BUG_TXEN
> /*
>* Do a quick test to see if we receive an
>* interrupt when we enable the TX irq.
> @@ -1660,7 +1661,9 @@ static int serial8250_startup(struct uar
> pr_debug("ttyS%d - enabling bad tx status
> workarounds\n",
>port->line);
> }
> - } else {
> + } else
> +#endif
> + {
> up->bugs &= ~UART_BUG_TXEN;
> }
>
> diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
> index 2978c09..7efcaf3 100644
> --- a/drivers/serial/Kconfig
> +++ b/drivers/serial/Kconfig
> @@ -223,6 +223,16 @@ config SERIAL_8250_DETECT_IRQ
>
> If unsure, say N.
>
> +config SERIAL_8250_DONT_TEST_BUG_TXEN
> + bool "Don't probe for TXEN bug"
> + depends on SERIAL_8250_EXTENDED
> + help
> + Say Y here if you don't want the kernel to probe for TXEN bug
> + on your serial port and try to workaround it. It might lead to
> + character loss on some boards, though this is quite a rare case.
> +
> + If unsure, say N.
> +
> config SERIAL_8250_RSA
> bool "Support RSA serial ports"
> depends on SERIAL_8250_EXTENDED
I think this should be a module option/boot parameter, not a config-time
option.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[PATCH] 8250: make probing for TXEN bug a config option
Hello Andrew,
probing for UART_BUG_TXEN in 8250 driver leads to weird effects on some ARM
boards (pnx4008 for instance). That is, the driver detects UART_BUG_TXEN
(though it apparently shouldn't) and it leads to symbol loss in console on
input (i. e. you input 'a' and you get nothing, then you input 'b' and you get
'a', then you input 'c' and get 'b' and so on).
The patch below makes this very probing a configuration option turned on by
default.
drivers/serial/8250.c |5 -
drivers/serial/Kconfig | 10 ++
2 files changed, 14 insertions(+), 1 deletion(-)
Signed-off-by: Vitaly Wool <[EMAIL PROTECTED]>
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index 51f3c73..cf3eb31 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -1645,6 +1645,7 @@ static int serial8250_startup(struct uar
serial8250_set_mctrl(&up->port, up->port.mctrl);
+#ifndef CONFIG_SERIAL_8250_DONT_TEST_BUG_TXEN
/*
* Do a quick test to see if we receive an
* interrupt when we enable the TX irq.
@@ -1660,7 +1661,9 @@ static int serial8250_startup(struct uar
pr_debug("ttyS%d - enabling bad tx status
workarounds\n",
port->line);
}
- } else {
+ } else
+#endif
+ {
up->bugs &= ~UART_BUG_TXEN;
}
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index 2978c09..7efcaf3 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -223,6 +223,16 @@ config SERIAL_8250_DETECT_IRQ
If unsure, say N.
+config SERIAL_8250_DONT_TEST_BUG_TXEN
+ bool "Don't probe for TXEN bug"
+ depends on SERIAL_8250_EXTENDED
+ help
+ Say Y here if you don't want the kernel to probe for TXEN bug
+ on your serial port and try to workaround it. It might lead to
+ character loss on some boards, though this is quite a rare case.
+
+ If unsure, say N.
+
config SERIAL_8250_RSA
bool "Support RSA serial ports"
depends on SERIAL_8250_EXTENDED
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
