> -----Original Message----- > From: linux-mmc-owner@xxxxxxxxxxxxxxx [mailto:linux-mmc- > owner@xxxxxxxxxxxxxxx] On Behalf Of Sujit Reddy Thumma > Sent: Monday, December 12, 2011 1:52 PM > To: linux-mmc@xxxxxxxxxxxxxxx > Cc: Sujit Reddy Thumma; cjb@xxxxxxxxxx > Subject: [PATCH] mmc: core: Ensure clocks are always enabled before > host interaction > > Ensure clocks are always enabled before any interaction with the > host controller driver. This makes sure that there is no race > between host execution and the core layer turning off clocks > in different context with clock gating framework. Thanks Sujit. We were seeing the race between mmc_host_clk_gate_delayed and execute_tuning(). Basically when host driver is in their execute_tuning() ops, mmc_host_clk_gate_delayed() may disable the clocks which may cause the execute_tuning() to fail. Your patch fixes this issue. Acked-by: Subhash Jadavani <subhashj@xxxxxxxxxxxxxx> > > Signed-off-by: Sujit Reddy Thumma <sthumma@xxxxxxxxxxxxxx> > --- > drivers/mmc/core/core.c | 19 ++++++++++++++++--- > drivers/mmc/core/host.h | 21 --------------------- > drivers/mmc/core/sd.c | 22 ++++++++++++++++++---- > drivers/mmc/core/sdio.c | 12 ++++++++++-- > drivers/mmc/core/sdio_irq.c | 10 ++++++++-- > include/linux/mmc/host.h | 19 +++++++++++++++++++ > 6 files changed, 71 insertions(+), 32 deletions(-) > > diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c > index a2aa860..03ad9fa 100644 > --- a/drivers/mmc/core/core.c > +++ b/drivers/mmc/core/core.c > @@ -290,8 +290,11 @@ static void mmc_wait_for_req_done(struct mmc_host > *host, > static void mmc_pre_req(struct mmc_host *host, struct mmc_request > *mrq, > bool is_first_req) > { > - if (host->ops->pre_req) > + if (host->ops->pre_req) { > + mmc_host_clk_hold(host); > host->ops->pre_req(host, mrq, is_first_req); > + mmc_host_clk_release(host); > + } > } > > /** > @@ -306,8 +309,11 @@ static void mmc_pre_req(struct mmc_host *host, > struct mmc_request *mrq, > static void mmc_post_req(struct mmc_host *host, struct mmc_request > *mrq, > int err) > { > - if (host->ops->post_req) > + if (host->ops->post_req) { > + mmc_host_clk_hold(host); > host->ops->post_req(host, mrq, err); > + mmc_host_clk_release(host); > + } > } > > /** > @@ -620,7 +626,9 @@ int mmc_host_enable(struct mmc_host *host) > int err; > > host->en_dis_recurs = 1; > + mmc_host_clk_hold(host); > err = host->ops->enable(host); > + mmc_host_clk_release(host); > host->en_dis_recurs = 0; > > if (err) { > @@ -640,7 +648,9 @@ static int mmc_host_do_disable(struct mmc_host > *host, int lazy) > int err; > > host->en_dis_recurs = 1; > + mmc_host_clk_hold(host); > err = host->ops->disable(host, lazy); > + mmc_host_clk_release(host); > host->en_dis_recurs = 0; > > if (err < 0) { > @@ -1203,8 +1213,11 @@ int mmc_set_signal_voltage(struct mmc_host > *host, int signal_voltage, bool cmd11 > > host->ios.signal_voltage = signal_voltage; > > - if (host->ops->start_signal_voltage_switch) > + if (host->ops->start_signal_voltage_switch) { > + mmc_host_clk_hold(host); > err = host->ops->start_signal_voltage_switch(host, &host- > >ios); > + mmc_host_clk_release(host); > + } > > return err; > } > diff --git a/drivers/mmc/core/host.h b/drivers/mmc/core/host.h > index fb8a5cd..08a7852 100644 > --- a/drivers/mmc/core/host.h > +++ b/drivers/mmc/core/host.h > @@ -14,27 +14,6 @@ > > int mmc_register_host_class(void); > void mmc_unregister_host_class(void); > - > -#ifdef CONFIG_MMC_CLKGATE > -void mmc_host_clk_hold(struct mmc_host *host); > -void mmc_host_clk_release(struct mmc_host *host); > -unsigned int mmc_host_clk_rate(struct mmc_host *host); > - > -#else > -static inline void mmc_host_clk_hold(struct mmc_host *host) > -{ > -} > - > -static inline void mmc_host_clk_release(struct mmc_host *host) > -{ > -} > - > -static inline unsigned int mmc_host_clk_rate(struct mmc_host *host) > -{ > - return host->ios.clock; > -} > -#endif > - > void mmc_host_deeper_disable(struct work_struct *work); > > #endif > diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c > index 6f27d35..b5212b8 100644 > --- a/drivers/mmc/core/sd.c > +++ b/drivers/mmc/core/sd.c > @@ -451,9 +451,11 @@ static int sd_select_driver_type(struct mmc_card > *card, u8 *status) > * information and let the hardware specific code > * return what is possible given the options > */ > + mmc_host_clk_hold(card->host); > drive_strength = card->host->ops->select_drive_strength( > card->sw_caps.uhs_max_dtr, > host_drv_type, card_drv_type); > + mmc_host_clk_release(card->host); > > err = mmc_sd_switch(card, 1, 2, drive_strength, status); > if (err) > @@ -660,8 +662,11 @@ static int mmc_sd_init_uhs_card(struct mmc_card > *card) > goto out; > > /* SPI mode doesn't define CMD19 */ > - if (!mmc_host_is_spi(card->host) && card->host->ops- > >execute_tuning) > + if (!mmc_host_is_spi(card->host) && card->host->ops- > >execute_tuning) { > + mmc_host_clk_hold(card->host); > err = card->host->ops->execute_tuning(card->host); > + mmc_host_clk_release(card->host); > + } > > out: > kfree(status); > @@ -849,8 +854,11 @@ int mmc_sd_setup_card(struct mmc_host *host, > struct mmc_card *card, > if (!reinit) { > int ro = -1; > > - if (host->ops->get_ro) > + if (host->ops->get_ro) { > + mmc_host_clk_hold(host); > ro = host->ops->get_ro(host); > + mmc_host_clk_release(host); > + } > > if (ro < 0) { > pr_warning("%s: host does not " > @@ -966,8 +974,11 @@ static int mmc_sd_init_card(struct mmc_host *host, > u32 ocr, > * Since initialization is now complete, enable preset > * value registers for UHS-I cards. > */ > - if (host->ops->enable_preset_value) > + if (host->ops->enable_preset_value) { > + mmc_host_clk_hold(host); > host->ops->enable_preset_value(host, true); > + mmc_host_clk_release(host); > + } > } else { > /* > * Attempt to change to high-speed (if supported) > @@ -1150,8 +1161,11 @@ int mmc_attach_sd(struct mmc_host *host) > return err; > > /* Disable preset value enable if already set since last time */ > - if (host->ops->enable_preset_value) > + if (host->ops->enable_preset_value) { > + mmc_host_clk_hold(host); > host->ops->enable_preset_value(host, false); > + mmc_host_clk_release(host); > + } > > err = mmc_send_app_op_cond(host, 0, &ocr); > if (err) > diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c > index b77f770..c9c2424 100644 > --- a/drivers/mmc/core/sdio.c > +++ b/drivers/mmc/core/sdio.c > @@ -438,9 +438,11 @@ static void sdio_select_driver_type(struct > mmc_card *card) > * information and let the hardware specific code > * return what is possible given the options > */ > + mmc_host_clk_hold(card->host); > drive_strength = card->host->ops->select_drive_strength( > card->sw_caps.uhs_max_dtr, > host_drv_type, card_drv_type); > + mmc_host_clk_release(card->host); > > /* if error just use default for drive strength B */ > err = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_DRIVE_STRENGTH, 0, > @@ -555,8 +557,11 @@ static int mmc_sdio_init_uhs_card(struct mmc_card > *card) > goto out; > > /* Initialize and start re-tuning timer */ > - if (!mmc_host_is_spi(card->host) && card->host->ops- > >execute_tuning) > + if (!mmc_host_is_spi(card->host) && card->host->ops- > >execute_tuning) { > + mmc_host_clk_hold(card->host); > err = card->host->ops->execute_tuning(card->host); > + mmc_host_clk_release(card->host); > + } > > out: > > @@ -626,8 +631,11 @@ static int mmc_sdio_init_card(struct mmc_host > *host, u32 ocr, > /* > * Call the optional HC's init_card function to handle quirks. > */ > - if (host->ops->init_card) > + if (host->ops->init_card) { > + mmc_host_clk_hold(host); > host->ops->init_card(host, card); > + mmc_host_clk_release(host); > + } > > /* > * If the host and card support UHS-I mode request the card > diff --git a/drivers/mmc/core/sdio_irq.c b/drivers/mmc/core/sdio_irq.c > index 68f81b9..f573e7f 100644 > --- a/drivers/mmc/core/sdio_irq.c > +++ b/drivers/mmc/core/sdio_irq.c > @@ -146,15 +146,21 @@ static int sdio_irq_thread(void *_host) > } > > set_current_state(TASK_INTERRUPTIBLE); > - if (host->caps & MMC_CAP_SDIO_IRQ) > + if (host->caps & MMC_CAP_SDIO_IRQ) { > + mmc_host_clk_hold(host); > host->ops->enable_sdio_irq(host, 1); > + mmc_host_clk_release(host); > + } > if (!kthread_should_stop()) > schedule_timeout(period); > set_current_state(TASK_RUNNING); > } while (!kthread_should_stop()); > > - if (host->caps & MMC_CAP_SDIO_IRQ) > + if (host->caps & MMC_CAP_SDIO_IRQ) { > + mmc_host_clk_hold(host); > host->ops->enable_sdio_irq(host, 0); > + mmc_host_clk_release(host); > + } > > pr_debug("%s: IRQ thread exiting with code %d\n", > mmc_hostname(host), ret); > diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h > index 9a03d03..aa2d7ee 100644 > --- a/include/linux/mmc/host.h > +++ b/include/linux/mmc/host.h > @@ -428,4 +428,23 @@ static inline int mmc_boot_partition_access(struct > mmc_host *host) > return !(host->caps2 & MMC_CAP2_BOOTPART_NOACC); > } > > +#ifdef CONFIG_MMC_CLKGATE > +void mmc_host_clk_hold(struct mmc_host *host); > +void mmc_host_clk_release(struct mmc_host *host); > +unsigned int mmc_host_clk_rate(struct mmc_host *host); > + > +#else > +static inline void mmc_host_clk_hold(struct mmc_host *host) > +{ > +} > + > +static inline void mmc_host_clk_release(struct mmc_host *host) > +{ > +} > + > +static inline unsigned int mmc_host_clk_rate(struct mmc_host *host) > +{ > + return host->ios.clock; > +} > +#endif > #endif /* LINUX_MMC_HOST_H */ > -- > Sent by a consultant of the Qualcomm Innovation Center, Inc. > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora > Forum. > > -- > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
