Re: [PATCH] mmc: core: Wait for command setting 'Power Off Notification' bit to complete

[Andrey Skvortsov <andrej.skvortzov@gmail.com>]

On 22-01-21 15:32, Ulf Hansson wrote:
> On Sat, 15 Jan 2022 at 13:15, Andrey Skvortsov
> <andrej.skvortzov@gmail.com> wrote:
> >
> > SD card is allowed to signal busy on DAT0 up to 1s after the
> > CMD49. According to SD spec (version 6.0 section 5.8.1.3) first host
> > waits until busy of CMD49 is released and only then polls Power
> > Management Status register up to 1s until the card indicates ready to
> > power off.
> >
> > Without waiting for busy before polling status register sometimes card
> > becomes unresponsive and system fails to suspend:
> >
> >   [  205.907459] Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done.
> >   [  206.421274] sunxi-mmc 1c0f000.mmc: data error, sending stop command
> >   [  206.421321] sunxi-mmc 1c0f000.mmc: send stop command failed
> >   [  206.421347] mmc0: error -110 reading status reg of PM func
> >   [  206.421366] PM: dpm_run_callback(): mmc_bus_suspend+0x0/0x74 returns -110
> >   [  206.421402] mmcblk mmc0:aaaa: PM: failed to suspend async: error -110
> >   [  206.437064] PM: Some devices failed to suspend, or early wake event detected
> >
> > Tested with Sandisk Extreme PRO A2 64GB on Allwinner A64 system.
> >
> > Signed-off-by: Andrey Skvortsov <andrej.skvortzov@gmail.com>
> 
> I did some tests at my side too, using a Qcom platform and it worked
> fine. However, I also used the same type of card as you, as I didn't
> have any other try with at this moment.

> So, applied for fixes and by adding a fixes/stable tag, thanks!
Thank you very much.
There is one another test report, that this patch fixes suspend with
KLEVV CRAS 128GB (K128GUSD6U3-CA). [1]

1. https://gitlab.com/mobian1/issues/-/issues/389#note_816636364

> I also did a minor amendment to the patch, see below.
> 
> Kind regards
> Uffe

-- 
Best regards,
Andrey Skvortsov