[PATCH] console: Use flush() before panic and reset
sr at denx.de
Thu Mar 16 10:00:09 CET 2023
On 3/15/23 21:29, Tony Dinh wrote:
> Hi Simon,
> On Wed, Mar 15, 2023 at 12:43 PM Simon Glass <sjg at chromium.org> wrote:
>> On Tue, 14 Mar 2023 at 18:24, Tony Dinh <mibodhi at gmail.com> wrote:
>>> To make sure the panic and the reset messages will go out, console flush() should be used.
>>> Sleep periods do not work in early u-boot phase when timer driver is not initialized yet.
>>> Reference: https://lists.denx.de/pipermail/u-boot/2023-March/512233.html
>>> Signed-off-by: Tony Dinh <mibodhi at gmail.com>
>>> arch/arm/lib/reset.c | 4 ++--
>>> lib/panic.c | 4 +++-
>>> 2 files changed, 5 insertions(+), 3 deletions(-)
>>> diff --git a/arch/arm/lib/reset.c b/arch/arm/lib/reset.c
>>> index 95169bae1c..3e051e36f1 100644
>>> --- a/arch/arm/lib/reset.c
>>> +++ b/arch/arm/lib/reset.c
>>> @@ -25,6 +25,7 @@
>>> #include <cpu_func.h>
>>> #include <irq_func.h>
>>> #include <linux/delay.h>
>>> +#include <stdio.h>
>> Reviewed-by: Simon Glass <sjg at chromium.org>
>> Is flush implemented widely?
> Pali wrote that flush function and here was his comment on the
> referenced thread:
> "Moreover there is already new function named flush() which
> does "wait until stdout message was sent" and can be used instead of
> those sleeps. I have already did it on some places (see git history for
> flush function) but seems that you find some more."
> So I think the answer is not yet widely implemented.
I just checked and it seems it's supported for all platforms using
DM_SERIAL when the serial driver supports the pending() function:
static void _serial_flush(struct udevice *dev)
struct dm_serial_ops *ops = serial_get_ops(dev);
while (ops->pending(dev, false) > 0)
So AFAICT it's implemented widely. Not sure, why
CONFIG_CONSOLE_FLUSH_SUPPORT was introduced. It's enabled by default
and should be available in all cases IMHO.
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