[Letux-kernel] mmc1 errors on Beaglebone Black since 5.17-rc3

Jean Rene Dawin jdawin at math.uni-bielefeld.de
Fri Feb 18 00:58:01 CET 2022


H. Nikolaus Schaller wrote on Thu 17/02/22 20:00:
> Fortunately I was able to set up a git bisect that can run unattended (by installing a new kernel over ethernet and running "reboot" instead of manually swapping µSD cards) and got:
> 
> 76bfc7ccc2fa9d382576f6013b57a0ef93d5a722 is the first bad commit
> commit 76bfc7ccc2fa9d382576f6013b57a0ef93d5a722
> Author: Huijin Park <huijin.park at samsung.com>
> Date:   Thu Nov 4 15:32:31 2021 +0900
> 
>    mmc: core: adjust polling interval for CMD1
> 
>    In mmc_send_op_cond(), loops are continuously performed at the same
>    interval of 10 ms.  However the behaviour is not good for some eMMC
>    which can be out from a busy state earlier than 10 ms if normal.
> 
>    Rather than fixing about the interval time in mmc_send_op_cond(),
>    let's instead convert into using the common __mmc_poll_for_busy().
> 
>    The reason for adjusting the interval time is that it is important
>    to reduce the eMMC initialization time, especially in devices that
>    use eMMC as rootfs.
> 
>    Test log(eMMC:KLM8G1GETF-B041):
> 
>    before: 12 ms (0.311016 - 0.298729)
>    [    0.295823] mmc0: starting CMD0 arg 00000000 flags 000000c0
>    [    0.298729] mmc0: starting CMD1 arg 40000080 flags 000000e1<-start
>    [    0.311016] mmc0: starting CMD1 arg 40000080 flags 000000e1<-finish
>    [    0.311336] mmc0: starting CMD2 arg 00000000 flags 00000007
> 
>    after: 2 ms (0.301270 - 0.298762)
>    [    0.295862] mmc0: starting CMD0 arg 00000000 flags 000000c0
>    [    0.298762] mmc0: starting CMD1 arg 40000080 flags 000000e1<-start
>    [    0.299067] mmc0: starting CMD1 arg 40000080 flags 000000e1
>    [    0.299441] mmc0: starting CMD1 arg 40000080 flags 000000e1
>    [    0.299879] mmc0: starting CMD1 arg 40000080 flags 000000e1
>    [    0.300446] mmc0: starting CMD1 arg 40000080 flags 000000e1
>    [    0.301270] mmc0: starting CMD1 arg 40000080 flags 000000e1<-finish
>    [    0.301572] mmc0: starting CMD2 arg 00000000 flags 00000007
> 
>    Signed-off-by: Huijin Park <huijin.park at samsung.com>
>    Link: https://lore.kernel.org/r/20211104063231.2115-3-huijin.park@samsung.com
>    Signed-off-by: Ulf Hansson <ulf.hansson at linaro.org>
> 
> Reverting this makes letux-5.17-rc[1-4] work.
> 
> Maybe you can try and confirm?

Hi Nikolaus,

yes, this fixes it for me, too. Thanks!

Regards,
Jean Rene


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