[PATCH] drivers: mmc: Reset watchdog when accessing mmc device

[Jaehoon Chung]

Hi,

> -----Original Message-----
> From: qianfan [mailto:qianfanguijin at 163.com]
> Sent: Tuesday, August 30, 2022 12:43 PM
> To: Jaehoon Chung <jh80.chung at samsung.com>; u-boot at lists.denx.de
> Cc: Peng Fan <peng.fan at nxp.com>
> Subject: Re: [PATCH] drivers: mmc: Reset watchdog when accessing mmc device
> 
> 
> 
> 在 2022/7/26 16:31, Jaehoon Chung 写道:
> > On 7/13/22 16:32, qianfanguijin at 163.com wrote:
> >> From: qianfan Zhao <qianfanguijin at 163.com>
> >>
> >> watchdog will reset when 'mmc read' or 'ext4load' a large file from
> >> mmc device. Reset watchdog when accessing mmc device.
> > I don't know why this patch is need.
> Hi:
> 
> maybe your's board doesn't have a hardware watchdog.
> on my board there has a gpio watchdog and we should trigger it no more than 1.2 second.
> otherwise it will reset CPU.
> 
> But 'mmc read' command doesn't trigger watchdog, it's ok if we load a smaller imges, but if we
> load a very bigger image which more than 100MiB, the watchdog will dead and trigger a system reset.

Sorry for too late. I had missed your email.
Is there a case to load more bigger image than 100MiB?

Best Regards,
Jaehoon Chung


> 
> So I make this patch to make sure we can trigger watchdog while loading mmc.
> >
> > Best Regards,
> > Jaehoon Chung
> >
> >> Signed-off-by: qianfan Zhao <qianfanguijin at 163.com>
> >> ---
> >>   drivers/mmc/mmc.c | 4 ++++
> >>   1 file changed, 4 insertions(+)
> >>
> >> diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c index
> >> 4d9871d69f..27ffdb7fa7 100644
> >> --- a/drivers/mmc/mmc.c
> >> +++ b/drivers/mmc/mmc.c
> >> @@ -24,6 +24,7 @@
> >>   #include <memalign.h>
> >>   #include <linux/list.h>
> >>   #include <div64.h>
> >> +#include <watchdog.h>
> >>   #include "mmc_private.h"
> >>
> >>   #define DEFAULT_CMD6_TIMEOUT_MS  500 @@ -297,6 +298,7 @@ int
> >> mmc_poll_for_busy(struct mmc *mmc, int timeout_ms)
> >>   		if (timeout_ms-- <= 0)
> >>   			break;
> >>
> >> +		WATCHDOG_RESET();
> >>   		udelay(1000);
> >>   	}
> >>
> >> @@ -500,6 +502,8 @@ ulong mmc_bread(struct blk_desc *block_dev, lbaint_t start, lbaint_t blkcnt,
> >>   		blocks_todo -= cur;
> >>   		start += cur;
> >>   		dst += cur * mmc->read_bl_len;
> >> +
> >> +		WATCHDOG_RESET();
> >>   	} while (blocks_todo > 0);
> >>
> >>   	return blkcnt;