[U-Boot] [PATCH] xyz-modem: Fix timeout loop waiting with WATCHDOG

[Lokesh Vutla]

Simon,

On 9/16/2017 9:43 PM, Simon Glass wrote:
> Hi,
> 
> On 16 September 2017 at 07:43, Tom Rini <trini at konsulko.com> wrote:
>> On Sat, Sep 16, 2017 at 05:14:31PM +0530, Lokesh Vutla wrote:
>>> Commit 2c77c0d6524eb ("xyz-modem: Change getc timeout loop waiting")
>>> fixes the loop delay when using a hw watchdog. But assuming that Watchdog
>>> kicking is taken care of by getc(). This is not true in case of DM_SERIAL.
>>> So, kick the watchdog before loop waiting, instead of relying on other
>>> functions.
>>>
>>> Signed-off-by: Lokesh Vutla <lokeshvutla at ti.com>
>>> ---
>>> - This fixes UART boot on AM335x-evm.
>>>
>>>  common/xyzModem.c | 2 ++
>>>  1 file changed, 2 insertions(+)
>>>
>>> diff --git a/common/xyzModem.c b/common/xyzModem.c
>>> index a0c5dfeece..8c4679473f 100644
>>> --- a/common/xyzModem.c
>>> +++ b/common/xyzModem.c
>>> @@ -26,6 +26,7 @@
>>>  #include <xyzModem.h>
>>>  #include <stdarg.h>
>>>  #include <crc.h>
>>> +#include <watchdog.h>
>>>
>>>  /* Assumption - run xyzModem protocol over the console port */
>>>
>>> @@ -64,6 +65,7 @@ CYGACC_COMM_IF_GETC_TIMEOUT (char chan, char *c)
>>>  {
>>>
>>>    ulong now = get_timer(0);
>>> +  WATCHDOG_RESET();
>>>    while (!tstc ())
>>>      {
>>>        if (get_timer(now) > xyzModem_CHAR_TIMEOUT)
>>
>> My worry is that other places also assume watchdog petted by getc().
>> Simon, is there a reason DM_SERIAL isn't doing what was done before?
>> Thanks!
> 
> This should really be fixed at source. Is the problems in
> _serial_tstc()? The watchdog is reset with _serial_getc().

Sorry, my bad. WATCHDOG_RESET() is being called in __serial_getc() when
err is -EAGAIN. But looks like it is never hitting this case. This way
ymodem fails as watchdog gets reset when downloading large files.

Thanks and regards,
Lokesh

> 
> Regards,
> Simon
>