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Date: Tue, 29 Mar 2016 12:47:12 +0200
Message-ID: <CAPDyKFqG1BHznSCHBrt7QMXNhiinVvO7=5gZJzLEeXG7EXKSOA@mail.gmail.com>
Subject: Re: [PATCH V3] mmc: sdhci: Fix regression setting power on Trats2 board
From: Ulf Hansson <ulf.hansson@linaro.org>
To: Adrian Hunter <adrian.hunter@intel.com>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>,
        Jisheng Zhang <jszhang@marvell.com>,
        Jaehoon Chung <jh80.chung@samsung.com>,
        Ludovic Desroches <ludovic.desroches@atmel.com>,
        "Ivan T. Ivanov" <ivan.ivanov@linaro.org>,
        linux-mmc <linux-mmc@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        linux-samsung-soc <linux-samsung-soc@vger.kernel.org>
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On 29 March 2016 at 11:45, Adrian Hunter <adrian.hunter@intel.com> wrote:
> Several commits relating to setting power have been introducing
> problems by putting driver-specific rules into generic SDHCI code.
>
> Krzysztof Kozlowski reported that after commit 918f4cbd4340 ("mmc:
> sdhci: restore behavior when setting VDD via external regulator")
> on Trats2 board there are warnings for invalid VDD  value (2.8V):
>
> [    3.119656] ------------[ cut here ]------------
> [    3.119666] WARNING: CPU: 3 PID: 90 at
> ../drivers/mmc/host/sdhci.c:1234 sdhci_do_set_ios+0x4cc/0x5e0
> [    3.119669] mmc0: Invalid vdd 0x10
> [    3.119673] Modules linked in:
> [    3.119679] CPU: 3 PID: 90 Comm: kworker/3:1 Tainted: G        W
>    4.5.0-next-20160324 #23
> [    3.119681] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
> [    3.119690] Workqueue: events_freezable mmc_rescan
> [    3.119708] [<c010e0ac>] (unwind_backtrace) from [<c010ae10>]
> (show_stack+0x10/0x14)
> [    3.119719] [<c010ae10>] (show_stack) from [<c0323260>]
> (dump_stack+0x88/0x9c)
> [    3.119728] [<c0323260>] (dump_stack) from [<c011b754>] (__warn+0xe8/0x100)
> [    3.119734] [<c011b754>] (__warn) from [<c011b7a4>]
> (warn_slowpath_fmt+0x38/0x48)
> [    3.119740] [<c011b7a4>] (warn_slowpath_fmt) from [<c0527d28>]
> (sdhci_do_set_ios+0x4cc/0x5e0)
> [    3.119748] [<c0527d28>] (sdhci_do_set_ios) from [<c0528018>]
> (sdhci_runtime_resume_host+0x60/0x114)
> [    3.119758] [<c0528018>] (sdhci_runtime_resume_host) from
> [<c0402570>] (__rpm_callback+0x2c/0x60)
> [    3.119767] [<c0402570>] (__rpm_callback) from [<c04025c4>]
> (rpm_callback+0x20/0x80)
> [    3.119773] [<c04025c4>] (rpm_callback) from [<c04034b8>]
> (rpm_resume+0x36c/0x558)
> [    3.119780] [<c04034b8>] (rpm_resume) from [<c04036f0>]
> (__pm_runtime_resume+0x4c/0x64)
> [    3.119788] [<c04036f0>] (__pm_runtime_resume) from [<c0512728>]
> (__mmc_claim_host+0x170/0x1b0)
> [    3.119795] [<c0512728>] (__mmc_claim_host) from [<c0514e2c>]
> (mmc_rescan+0x54/0x348)
> [    3.119807] [<c0514e2c>] (mmc_rescan) from [<c0130dac>]
> (process_one_work+0x120/0x3f4)
> [    3.119815] [<c0130dac>] (process_one_work) from [<c01310b8>]
> (worker_thread+0x38/0x554)
> [    3.119823] [<c01310b8>] (worker_thread) from [<c01365a4>]
> (kthread+0xdc/0xf4)
> [    3.119831] [<c01365a4>] (kthread) from [<c0107878>]
> (ret_from_fork+0x14/0x3c)
> [    3.119834] ---[ end trace a22d652aa3276886 ]---
>
> Fix by adding a 'set_power' callback and restoring the default
> behaviour prior to commit 918f4cbd4340 ("mmc: sdhci: restore
> behavior when setting VDD via external regulator").  The desired
> behaviour of that commit is gotten by having sdhci-pxav3 provide
> its own set_power callback.
>
> Reported-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
> Link: http://lkml.kernel.org/r/CAJKOXPcGDnPm-Ykh6wHqV1YxfTaov5E8iVqBoBn4OJc7BnhgEQ@mail.gmail.com
> Fixes: 918f4cbd4340 ("mmc: sdhci: restore behavior when setting VDD...)
> Tested-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
> Tested-by: Ludovic Desroches <ludovic.desroches@atmel.com>
> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
> Cc: stable@vger.kernel.org # v4.5+

Thanks, applied for fixes!

Kind regards
Uffe

> ---
>
>
> Changes in V3:
>
>         Expanded commit message.
>
>         Removed redundant vdd = 0 from sdhci_set_power()
>
>         Make pxav3_set_power() check the regulator was created successfully
>         before using it, and ensure vdd is 0 when pwr is 0.
>
>
>  drivers/mmc/host/sdhci-pxav3.c | 22 ++++++++++++++++++++++
>  drivers/mmc/host/sdhci.c       | 39 ++++++++++++++++++++++++++++++---------
>  drivers/mmc/host/sdhci.h       |  4 ++++
>  3 files changed, 56 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci-pxav3.c b/drivers/mmc/host/sdhci-pxav3.c
> index f5edf9d3a18a..0535827b02ee 100644
> --- a/drivers/mmc/host/sdhci-pxav3.c
> +++ b/drivers/mmc/host/sdhci-pxav3.c
> @@ -307,8 +307,30 @@ static void pxav3_set_uhs_signaling(struct sdhci_host *host, unsigned int uhs)
>                 __func__, uhs, ctrl_2);
>  }
>
> +static void pxav3_set_power(struct sdhci_host *host, unsigned char mode,
> +                           unsigned short vdd)
> +{
> +       struct mmc_host *mmc = host->mmc;
> +       u8 pwr = host->pwr;
> +
> +       sdhci_set_power(host, mode, vdd);
> +
> +       if (host->pwr == pwr)
> +               return;
> +
> +       if (host->pwr == 0)
> +               vdd = 0;
> +
> +       if (!IS_ERR(mmc->supply.vmmc)) {
> +               spin_unlock_irq(&host->lock);
> +               mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd);
> +               spin_lock_irq(&host->lock);
> +       }
> +}
> +
>  static const struct sdhci_ops pxav3_sdhci_ops = {
>         .set_clock = sdhci_set_clock,
> +       .set_power = pxav3_set_power,
>         .platform_send_init_74_clocks = pxav3_gen_init_74_clocks,
>         .get_max_clock = sdhci_pltfm_clk_get_max_clock,
>         .set_bus_width = sdhci_set_bus_width,
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index add9fdfd1d8f..f5b52b4308cc 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -1269,10 +1269,24 @@ clock_set:
>  }
>  EXPORT_SYMBOL_GPL(sdhci_set_clock);
>
> -static void sdhci_set_power(struct sdhci_host *host, unsigned char mode,
> -                           unsigned short vdd)
> +static void sdhci_set_power_reg(struct sdhci_host *host, unsigned char mode,
> +                               unsigned short vdd)
>  {
>         struct mmc_host *mmc = host->mmc;
> +
> +       spin_unlock_irq(&host->lock);
> +       mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd);
> +       spin_lock_irq(&host->lock);
> +
> +       if (mode != MMC_POWER_OFF)
> +               sdhci_writeb(host, SDHCI_POWER_ON, SDHCI_POWER_CONTROL);
> +       else
> +               sdhci_writeb(host, 0, SDHCI_POWER_CONTROL);
> +}
> +
> +void sdhci_set_power(struct sdhci_host *host, unsigned char mode,
> +                    unsigned short vdd)
> +{
>         u8 pwr = 0;
>
>         if (mode != MMC_POWER_OFF) {
> @@ -1304,7 +1318,6 @@ static void sdhci_set_power(struct sdhci_host *host, unsigned char mode,
>                 sdhci_writeb(host, 0, SDHCI_POWER_CONTROL);
>                 if (host->quirks2 & SDHCI_QUIRK2_CARD_ON_NEEDS_BUS_ON)
>                         sdhci_runtime_pm_bus_off(host);
> -               vdd = 0;
>         } else {
>                 /*
>                  * Spec says that we should clear the power reg before setting
> @@ -1335,12 +1348,20 @@ static void sdhci_set_power(struct sdhci_host *host, unsigned char mode,
>                 if (host->quirks & SDHCI_QUIRK_DELAY_AFTER_POWER)
>                         mdelay(10);
>         }
> +}
> +EXPORT_SYMBOL_GPL(sdhci_set_power);
>
> -       if (!IS_ERR(mmc->supply.vmmc)) {
> -               spin_unlock_irq(&host->lock);
> -               mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd);
> -               spin_lock_irq(&host->lock);
> -       }
> +static void __sdhci_set_power(struct sdhci_host *host, unsigned char mode,
> +                             unsigned short vdd)
> +{
> +       struct mmc_host *mmc = host->mmc;
> +
> +       if (host->ops->set_power)
> +               host->ops->set_power(host, mode, vdd);
> +       else if (!IS_ERR(mmc->supply.vmmc))
> +               sdhci_set_power_reg(host, mode, vdd);
> +       else
> +               sdhci_set_power(host, mode, vdd);
>  }
>
>  /*****************************************************************************\
> @@ -1490,7 +1511,7 @@ static void sdhci_do_set_ios(struct sdhci_host *host, struct mmc_ios *ios)
>                 }
>         }
>
> -       sdhci_set_power(host, ios->power_mode, ios->vdd);
> +       __sdhci_set_power(host, ios->power_mode, ios->vdd);
>
>         if (host->ops->platform_send_init_74_clocks)
>                 host->ops->platform_send_init_74_clocks(host, ios->power_mode);
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index 0115e9907bf8..033d72b5bbd5 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -529,6 +529,8 @@ struct sdhci_ops {
>  #endif
>
>         void    (*set_clock)(struct sdhci_host *host, unsigned int clock);
> +       void    (*set_power)(struct sdhci_host *host, unsigned char mode,
> +                            unsigned short vdd);
>
>         int             (*enable_dma)(struct sdhci_host *host);
>         unsigned int    (*get_max_clock)(struct sdhci_host *host);
> @@ -660,6 +662,8 @@ static inline bool sdhci_sdio_irq_enabled(struct sdhci_host *host)
>  }
>
>  void sdhci_set_clock(struct sdhci_host *host, unsigned int clock);
> +void sdhci_set_power(struct sdhci_host *host, unsigned char mode,
> +                    unsigned short vdd);
>  void sdhci_set_bus_width(struct sdhci_host *host, int width);
>  void sdhci_reset(struct sdhci_host *host, u8 mask);
>  void sdhci_set_uhs_signaling(struct sdhci_host *host, unsigned timing);
> --
> 1.9.1
>
>