From: Raul Rangel <rrangel@chromium.org>
To: Ulf Hansson <ulf.hansson@linaro.org>
Cc: "linux-mmc@vger.kernel.org" <linux-mmc@vger.kernel.org>,
Daniel Kurtz <djkurtz@chromium.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Adrian Hunter <adrian.hunter@intel.com>
Subject: Re: [RFC PATCH 2/2] mmc: sdhci: Quirk for AMD SDHC Device 0x7906
Date: Mon, 3 Jun 2019 14:34:08 -0600 [thread overview]
Message-ID: <20190603203408.GB182838@google.com> (raw)
In-Reply-To: <CAPDyKFq8T0kdJsPfk6ue2OaQUO9L_oOwnxDw=-FVboZRyKJPdA@mail.gmail.com>
On Tue, May 28, 2019 at 09:41:07AM +0200, Ulf Hansson wrote:
> On Wed, 1 May 2019 at 19:55, Raul E Rangel <rrangel@chromium.org> wrote:
> >
> > AMD SDHC 0x7906 requires a hard reset to clear all internal state.
> > Otherwise it can get into a bad state where the DATA lines are always
> > read as zeros.
> >
> > This change requires firmware that can transition the device into
> > D3Cold for it to work correctly. If the firmware does not support
> > transitioning to D3Cold then the power state transitions are a no-op.
> >
> > Signed-off-by: Raul E Rangel <rrangel@chromium.org>
>
> Does this also solve the problem you tried to fix in patch1, without patch1?
Patch one is required. Otherwise there is a possible race condition
where the card remove is not detected. I'll go through the comments you
added on the first patch.
>
> Should this have a stable tag?
I would not put a stable tag on this patch series yet because there is a
possible resource leak in 4.14. See https://lkml.org/lkml/2019/5/13/763
If we can get those patched merged then I think it's fine to backport
the patch set. 4.19 doesn't suffer from the resource leak. I haven't
audited anything before 4.14 though.
Thanks,
Raul
>
> Kind regards
> Uffe
>
> > ---
> >
> > drivers/mmc/host/sdhci-pci-core.c | 51 ++++++++++++++++++++++++++++++-
> > 1 file changed, 50 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c
> > index 99b0fec2836b..532fbcbd373b 100644
> > --- a/drivers/mmc/host/sdhci-pci-core.c
> > +++ b/drivers/mmc/host/sdhci-pci-core.c
> > @@ -25,6 +25,7 @@
> > #include <linux/mmc/mmc.h>
> > #include <linux/scatterlist.h>
> > #include <linux/io.h>
> > +#include <linux/iopoll.h>
> > #include <linux/gpio.h>
> > #include <linux/pm_runtime.h>
> > #include <linux/mmc/slot-gpio.h>
> > @@ -1498,11 +1499,59 @@ static int amd_probe(struct sdhci_pci_chip *chip)
> > return 0;
> > }
> >
> > +static u32 sdhci_read_present_state(struct sdhci_host *host)
> > +{
> > + return sdhci_readl(host, SDHCI_PRESENT_STATE);
> > +}
> > +
> > +void amd_sdhci_reset(struct sdhci_host *host, u8 mask)
> > +{
> > + struct sdhci_pci_slot *slot = sdhci_priv(host);
> > + struct pci_dev *pdev = slot->chip->pdev;
> > + u32 present_state;
> > +
> > + /*
> > + * SDHC 0x7906 requires a hard reset to clear all internal state.
> > + * Otherwise it can get into a bad state where the DATA lines are always
> > + * read as zeros.
> > + */
> > + if (pdev->device == 0x7906 && (mask & SDHCI_RESET_ALL)) {
> > + pci_clear_master(pdev);
> > +
> > + pci_save_state(pdev);
> > +
> > + pci_set_power_state(pdev, PCI_D3cold);
> > + pr_debug("%s: power_state=%u\n", mmc_hostname(host->mmc),
> > + pdev->current_state);
> > + pci_set_power_state(pdev, PCI_D0);
> > +
> > + pci_restore_state(pdev);
> > +
> > + /*
> > + * SDHCI_RESET_ALL says the card detect logic should not be
> > + * reset, but since we need to reset the entire controller
> > + * we should wait until the card detect logic has stabilized.
> > + *
> > + * This normally takes about 40ms.
> > + */
> > + readx_poll_timeout(
> > + sdhci_read_present_state,
> > + host,
> > + present_state,
> > + present_state & SDHCI_CD_STABLE,
> > + 10000,
> > + 100000
> > + );
> > + }
> > +
> > + return sdhci_reset(host, mask);
> > +}
> > +
> > static const struct sdhci_ops amd_sdhci_pci_ops = {
> > .set_clock = sdhci_set_clock,
> > .enable_dma = sdhci_pci_enable_dma,
> > .set_bus_width = sdhci_set_bus_width,
> > - .reset = sdhci_reset,
> > + .reset = amd_sdhci_reset,
> > .set_uhs_signaling = sdhci_set_uhs_signaling,
> > };
> >
> > --
> > 2.21.0.593.g511ec345e18-goog
> >
next prev parent reply other threads:[~2019-06-03 20:34 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-01 17:54 [RFC PATCH 1/2] mmc: sdhci: Manually check card status after reset Raul E Rangel
2019-05-01 17:54 ` [RFC PATCH 2/2] mmc: sdhci: Quirk for AMD SDHC Device 0x7906 Raul E Rangel
2019-05-02 6:32 ` Adrian Hunter
2019-05-02 15:42 ` Raul Rangel
2019-05-12 17:04 ` S-k, Shyam-sundar
2019-05-13 6:44 ` Adrian Hunter
2019-05-28 7:41 ` Ulf Hansson
2019-06-03 20:34 ` Raul Rangel [this message]
2019-05-03 15:12 ` [RFC PATCH 1/2] mmc: sdhci: Manually check card status after reset Raul Rangel
2019-05-08 19:00 ` Raul Rangel
2019-05-28 7:38 ` Ulf Hansson
2019-06-07 16:05 ` Raul Rangel
2019-06-10 16:17 ` Ulf Hansson
2019-06-10 16:32 ` Raul Rangel
2019-06-11 10:30 ` Adrian Hunter
2019-06-19 14:56 ` Raul Rangel
2019-08-01 15:16 ` Raul Rangel
2019-08-02 4:58 ` Adrian Hunter
2019-08-05 16:49 ` Raul Rangel
2019-08-06 5:51 ` Adrian Hunter
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