From: Doug Anderson <dianders@chromium.org>
To: Matthias Kaehlcke <mka@chromium.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>,
LKML <linux-kernel@vger.kernel.org>,
Linux MMC List <linux-mmc@vger.kernel.org>
Subject: Re: [PATCH 2/2] mmc: core: Run handlers for pending SDIO interrupts on resume
Date: Thu, 29 Aug 2019 10:44:17 -0700 [thread overview]
Message-ID: <CAD=FV=UhKCKzj7W+LGAGuzukCsOag1meHk4dW7=XQF21KeS_pg@mail.gmail.com> (raw)
In-Reply-To: <20190828214620.66003-2-mka@chromium.org>
Hi,
On Wed, Aug 28, 2019 at 2:46 PM Matthias Kaehlcke <mka@chromium.org> wrote:
>
> With commit 83293386bc95 ("mmc: core: Prevent processing SDIO IRQs
> when the card is suspended") SDIO interrupts are dropped if they
> occur while the card is suspended. Dropping the interrupts can cause
> problems after resume with cards that remain powered during suspend
> and preserve their state. These cards may end up in an inconsistent
> state since the event that triggered the interrupt is never processed
> and remains pending. One example is the Bluetooth function of the
> Marvell 8997, SDIO is broken on resume (for both Bluetooth and WiFi)
> when processing of a pending HCI event is skipped.
>
> For cards that remained powered during suspend check on resume if
> SDIO interrupts are pending, and trigger interrupt processing if
> needed.
>
> Fixes: 83293386bc95 ("mmc: core: Prevent processing SDIO IRQs when the card is suspended")
> Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
> ---
> drivers/mmc/core/sdio.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
> index 8dd8fc32ecca..a6b4742a91c6 100644
> --- a/drivers/mmc/core/sdio.c
> +++ b/drivers/mmc/core/sdio.c
> @@ -975,6 +975,7 @@ static int mmc_sdio_suspend(struct mmc_host *host)
> static int mmc_sdio_resume(struct mmc_host *host)
> {
> int err = 0;
> + u8 pending = 0;
>
> /* Basic card reinitialization. */
> mmc_claim_host(host);
> @@ -1009,6 +1010,14 @@ static int mmc_sdio_resume(struct mmc_host *host)
> /* Allow SDIO IRQs to be processed again. */
> mmc_card_clr_suspended(host->card);
>
> + if (!mmc_card_keep_power(host))
> + goto skip_pending_irqs;
> +
> + if (!sdio_get_pending_irqs(host, &pending) &&
> + pending != 0)
> + sdio_signal_irq(host);
> +
> +skip_pending_irqs:
> if (host->sdio_irqs) {
nit: I'd prefer to avoid the "goto" if possible. Using "goto" to
handle unwinding during error handling always makes good sent to me,
but here you're not doing unwinding--you're just using the "goto" as
an unstructured "if". I'd rather just see:
if (mmc_card_keep_power(host) &&
!sdio_get_pending_irqs(host, &pending) && pending != 0)
sdio_signal_irq(host);
Other than that this patch seems sane to me though (obviously) the
person you'd need to convince is Ulf. ;-)
-Doug
next prev parent reply other threads:[~2019-08-29 17:44 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-28 21:46 [PATCH 1/2] mmc: sdio: Move code to get pending SDIO IRQs to a function Matthias Kaehlcke
2019-08-28 21:46 ` [PATCH 2/2] mmc: core: Run handlers for pending SDIO interrupts on resume Matthias Kaehlcke
2019-08-29 8:48 ` Ulf Hansson
2019-08-29 17:15 ` Matthias Kaehlcke
2019-08-29 17:39 ` Doug Anderson
2019-08-30 6:08 ` Ulf Hansson
2019-08-30 10:38 ` Ulf Hansson
2019-08-29 17:44 ` Doug Anderson [this message]
2019-08-29 8:29 ` [PATCH 1/2] mmc: sdio: Move code to get pending SDIO IRQs to a function Ulf Hansson
2019-08-29 17:25 ` Matthias Kaehlcke
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAD=FV=UhKCKzj7W+LGAGuzukCsOag1meHk4dW7=XQF21KeS_pg@mail.gmail.com' \
--to=dianders@chromium.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mmc@vger.kernel.org \
--cc=mka@chromium.org \
--cc=ulf.hansson@linaro.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).