Re: [PATCH] mmc: sdhci-pci: Fix initialization of some SD cards for Intel BYT-based controllers

From: Ulf Hansson <ulf.hansson@linaro.org>
To: Adrian Hunter <adrian.hunter@intel.com>
Cc: linux-mmc <linux-mmc@vger.kernel.org>
Subject: Re: [PATCH] mmc: sdhci-pci: Fix initialization of some SD cards for Intel BYT-based controllers
Date: Wed, 31 Mar 2021 14:51:56 +0200	[thread overview]
Message-ID: <CAPDyKFpbA4x33yr4s7+csATm6zgsx=NA4Ya-_QZBUPzNqEGoqQ@mail.gmail.com> (raw)
In-Reply-To: <20210331081752.23621-1-adrian.hunter@intel.com>

On Wed, 31 Mar 2021 at 10:17, Adrian Hunter <adrian.hunter@intel.com> wrote:
>
> Bus power may control card power, but the full reset done by SDHCI at
> initialization still may not reset the power, whereas a direct write to
> SDHCI_POWER_CONTROL can. That might be needed to initialize correctly, if
> the card was left powered on previously.
>
> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
> Cc: stable@vger.kernel.org

Applied for next, thanks!

Kind regards
Uffe

> ---
>  drivers/mmc/host/sdhci-pci-core.c | 27 +++++++++++++++++++++++++++
>  1 file changed, 27 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c
> index b3caa174effe..be19785227fe 100644
> --- a/drivers/mmc/host/sdhci-pci-core.c
> +++ b/drivers/mmc/host/sdhci-pci-core.c
> @@ -516,6 +516,7 @@ struct intel_host {
>         int     drv_strength;
>         bool    d3_retune;
>         bool    rpm_retune_ok;
> +       bool    needs_pwr_off;
>         u32     glk_rx_ctrl1;
>         u32     glk_tun_val;
>         u32     active_ltr;
> @@ -643,9 +644,25 @@ static int bxt_get_cd(struct mmc_host *mmc)
>  static void sdhci_intel_set_power(struct sdhci_host *host, unsigned char mode,
>                                   unsigned short vdd)
>  {
> +       struct sdhci_pci_slot *slot = sdhci_priv(host);
> +       struct intel_host *intel_host = sdhci_pci_priv(slot);
>         int cntr;
>         u8 reg;
>
> +       /*
> +        * Bus power may control card power, but a full reset still may not
> +        * reset the power, whereas a direct write to SDHCI_POWER_CONTROL can.
> +        * That might be needed to initialize correctly, if the card was left
> +        * powered on previously.
> +        */
> +       if (intel_host->needs_pwr_off) {
> +               intel_host->needs_pwr_off = false;
> +               if (mode != MMC_POWER_OFF) {
> +                       sdhci_writeb(host, 0, SDHCI_POWER_CONTROL);
> +                       usleep_range(10000, 12500);
> +               }
> +       }
> +
>         sdhci_set_power(host, mode, vdd);
>
>         if (mode == MMC_POWER_OFF)
> @@ -1135,6 +1152,14 @@ static int byt_sdio_probe_slot(struct sdhci_pci_slot *slot)
>         return 0;
>  }
>
> +static void byt_needs_pwr_off(struct sdhci_pci_slot *slot)
> +{
> +       struct intel_host *intel_host = sdhci_pci_priv(slot);
> +       u8 reg = sdhci_readb(slot->host, SDHCI_POWER_CONTROL);
> +
> +       intel_host->needs_pwr_off = reg  & SDHCI_POWER_ON;
> +}
> +
>  static int byt_sd_probe_slot(struct sdhci_pci_slot *slot)
>  {
>         byt_probe_slot(slot);
> @@ -1152,6 +1177,8 @@ static int byt_sd_probe_slot(struct sdhci_pci_slot *slot)
>             slot->chip->pdev->subsystem_device == PCI_SUBDEVICE_ID_NI_78E3)
>                 slot->host->mmc->caps2 |= MMC_CAP2_AVOID_3_3V;
>
> +       byt_needs_pwr_off(slot);
> +
>         return 0;
>  }
>
> --
> 2.17.1
>