Re: [PATCH] kernel/printk.c: Concerns about the console handover
- From: Russell King <rmk+lkml@xxxxxxxxxxxxxxxx>
- Date: Fri, 21 Sep 2007 14:43:32 +0100
On Fri, Sep 21, 2007 at 02:36:50PM +0100, Maciej W. Rozycki wrote:
On Fri, 21 Sep 2007, Andrew Morton wrote:
It would be useful to have some basic information like: Which kernel
version was this found in? Which kernel version last worked?
The kernel used was a 2.6.23-rc5 snapshot from Sep 4th, 2007 taken from
the linux-mips.org tree (as stated by the revision of the patch provided).
There is no version that can be considered working as the change to add
the printk() to register_console() went in before drivers/serial/zs.c was
added and the old drivers/tc/zs.c driver might have been to sloppy to
handle such bits as the transmitter enable properly. I may investigate.
Chances are nobody tried any version of the kernel from the period
between the printk() was added and drivers/tc/zs.c removed with the
DECstation; I have not.
Anyway, I did confirm keeping the transmitter enabled all the time makes
the problem go away.
I suspect the correct fix for this is to take the fix in the ARM tree
for serial_core's console initialisation, and ensure that zs.c handles
the power management of the port (enabling/disabling transmitter)
in the power management callback.
You can find the fix in the mbox archive:
http://ftp.arm.linux.org.uk/pub/linux/arm/kernel/git-cut/arm:devel.mbox
--
Russell King
Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
maintainer of:
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
- Follow-Ups:
- Re: [PATCH] kernel/printk.c: Concerns about the console handover
- From: Maciej W. Rozycki
- Re: [PATCH] kernel/printk.c: Concerns about the console handover
- References:
- [PATCH] kernel/printk.c: Concerns about the console handover
- From: Maciej W. Rozycki
- Re: [PATCH] kernel/printk.c: Concerns about the console handover
- From: Andrew Morton
- Re: [PATCH] kernel/printk.c: Concerns about the console handover
- From: Maciej W. Rozycki
- [PATCH] kernel/printk.c: Concerns about the console handover
- Prev by Date: USB autosuspend and turning of usb pendrive leds
- Next by Date: Re: [PATCH -mm] Don't truncate /proc/PID/environ at 4096 characters
- Previous by thread: Re: [PATCH] kernel/printk.c: Concerns about the console handover
- Next by thread: Re: [PATCH] kernel/printk.c: Concerns about the console handover
- Index(es):
Relevant Pages
|
