[lkml]   [2019]   [Apr]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH] mmc: dw_mmc: Disable SDIO interrupts while suspended to fix suspend/resume

On Wed, Apr 10, 2019 at 3:13 PM Douglas Anderson <> wrote:
> Processing SDIO interrupts while dw_mmc is suspended (or partly
> suspended) seems like a bad idea. We really don't want to be
> processing them until we've gotten ourselves fully powered up.
> You might be wondering how it's even possible to become suspended when
> an SDIO interrupt is active. As can be seen in
> dw_mci_enable_sdio_irq(), we explicitly keep dw_mmc out of runtime
> suspend when the SDIO interrupt is enabled. ...but even though we
> stop normal runtime suspend transitions when SDIO interrupts are
> enabled, the dw_mci_runtime_suspend() can still get called for a full
> system suspend.
> Let's handle all this by explicitly masking SDIO interrupts in the
> suspend call and unmasking them later in the resume call. To do this
> cleanly I'll keep track of whether the client requested that SDIO
> interrupts be enabled so that we can reliably restore them regardless
> of whether we're masking them for one reason or another.
> Without this fix it can be seen that rk3288-veyron Chromebooks with
> Marvell WiFi would sometimes fail to resume WiFi even after picking my
> recent mwifiex patch [1]. Specifically you'd see messages like this:
> mwifiex_sdio mmc1:0001:1: Firmware wakeup failed
> mwifiex_sdio mmc1:0001:1: PREP_CMD: FW in reset state
> ...and tracing through the resume code in the failing cases showed
> that we were processing a SDIO interrupt really early in the resume
> call.
> NOTE: downstream in Chrome OS 3.14 and 3.18 kernels (both of which
> support the Marvell SDIO WiFi card) we had a patch ("CHROMIUM: sdio:
> Defer SDIO interrupt handling until after resume") [2]. Presumably
> this is the same problem that was solved by that patch.
> [1]
> [2]
> Cc: <>
> Signed-off-by: Douglas Anderson <>
> ---
> I didn't put any "Fixes" tag here, but presumably this could be
> backported to whichever kernels folks found it useful for. I have at
> least confirmed that kernels v4.14 and v4.19 (as well as v5.1-rc2)
> show the problem. It is very easy to pick this to v4.19 and it
> definitely fixes the problem there.
> I haven't spent the time to pick this to 4.14 myself, but presumably
> it wouldn't be too hard to backport this as far as v4.13 since that
> contains commit 32dba73772f8 ("mmc: dw_mmc: Convert to use
> MMC_CAP2_SDIO_IRQ_NOTHREAD for SDIO IRQs"). Prior to that it might
> make sense for anyone experiencing this problem to just pick the old
> CHROMIUM patch to fix them.
> drivers/mmc/host/dw_mmc.c | 24 ++++++++++++++++++++----
> drivers/mmc/host/dw_mmc.h | 3 +++
> 2 files changed, 23 insertions(+), 4 deletions(-)

Jaehoon / Shawn: any thoughts on this patch?


 \ /
  Last update: 2019-04-22 17:22    [W:0.067 / U:5.452 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site