From e9ce2ce17da626d930812199568bd426b2832f57 Mon Sep 17 00:00:00 2001 From: Ulf Hansson Date: Fri, 12 Feb 2021 14:16:10 +0100 Subject: mmc: core: Drop reference counting of the bus_ops When the mmc_rescan work is enabled for execution (host->rescan_disable), it's the only instance per mmc host that is allowed to set/clear the host->bus_ops pointer. Besides the mmc_rescan work, there are a couple of scenarios when the host->bus_ops pointer may be accessed. Typically, those can be described as as below: *) Upper mmc driver layers (like the mmc block device driver or an SDIO functional driver) needs to execute a host->bus_ops callback. This can be considered as safe without having to use some special locking mechanism, because they operate on top of the struct mmc_card. As long as there is a card to operate upon, the mmc core guarantees that there is a host->bus_ops assigned as well. Note that, upper layer mmc drivers are of course responsible to clean up from themselves from their ->remove() callbacks, otherwise things would fall apart anyways. **) Via the mmc host instance, we may need to force a removal of an inserted mmc card. This happens when a mmc host driver gets unbind, for example. In this case, we protect the host->bus_ops pointer from concurrent accesses, by disabling the mmc_rescan work upfront (host->rescan_disable). See mmc_stop_host() for example. This said, it seems like the reference counting of the host->bus_ops pointer at some point have become superfluous. As this is an old mechanism of the mmc core, it a bit difficult to digest the history of when that could have happened. However, let's drop the reference counting to avoid unnecessary code-paths and lockings. Cc: Pierre Ossman Cc: Russell King Signed-off-by: Ulf Hansson Reviewed-by: Adrian Hunter Link: https://lore.kernel.org/r/20210212131610.236843-1-ulf.hansson@linaro.org --- include/linux/mmc/host.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index 26a3c7bc29ae..a001ad2f5f23 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -423,7 +423,6 @@ struct mmc_host { /* group bitfields together to minimize padding */ unsigned int use_spi_crc:1; unsigned int claimed:1; /* host exclusively claimed */ - unsigned int bus_dead:1; /* bus has been released */ unsigned int doing_init_tune:1; /* initial tuning in progress */ unsigned int can_retune:1; /* re-tuning can be used */ unsigned int doing_retune:1; /* re-tuning in progress */ @@ -454,7 +453,6 @@ struct mmc_host { struct mmc_slot slot; const struct mmc_bus_ops *bus_ops; /* current bus driver */ - unsigned int bus_refs; /* reference counter */ unsigned int sdio_irqs; struct task_struct *sdio_irq_thread; -- cgit From 18bbda900ffa7770b93daa1bc1ce3be39e643101 Mon Sep 17 00:00:00 2001 From: Jisheng Zhang Date: Thu, 11 Mar 2021 17:41:57 +0800 Subject: mmc: sdio: fix a typo in the comment of SDIO_SD_REV_3_00 I believe "Spev" is typo, should be "Spec". Signed-off-by: Jisheng Zhang Link: https://lore.kernel.org/r/20210311174157.561dada9@xhacker.debian Signed-off-by: Ulf Hansson --- include/linux/mmc/sdio.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/mmc/sdio.h b/include/linux/mmc/sdio.h index e28769991e82..2a05d1ac4f0e 100644 --- a/include/linux/mmc/sdio.h +++ b/include/linux/mmc/sdio.h @@ -82,7 +82,7 @@ #define SDIO_SD_REV_1_01 0 /* SD Physical Spec Version 1.01 */ #define SDIO_SD_REV_1_10 1 /* SD Physical Spec Version 1.10 */ #define SDIO_SD_REV_2_00 2 /* SD Physical Spec Version 2.00 */ -#define SDIO_SD_REV_3_00 3 /* SD Physical Spev Version 3.00 */ +#define SDIO_SD_REV_3_00 3 /* SD Physical Spec Version 3.00 */ #define SDIO_CCCR_IOEx 0x02 #define SDIO_CCCR_IORx 0x03 -- cgit From 17a17bf50612e6048a9975450cf1bd30f93815b5 Mon Sep 17 00:00:00 2001 From: Ulf Hansson Date: Wed, 10 Mar 2021 16:29:00 +0100 Subject: mmc: core: Fix hanging on I/O during system suspend for removable cards The mmc core uses a PM notifier to temporarily during system suspend, turn off the card detection mechanism for removal/insertion of (e)MMC/SD/SDIO cards. Additionally, the notifier may be used to remove an SDIO card entirely, if a corresponding SDIO functional driver don't have the system suspend/resume callbacks assigned. This behaviour has been around for a very long time. However, a recent bug report tells us there are problems with this approach. More precisely, when receiving the PM_SUSPEND_PREPARE notification, we may end up hanging on I/O to be completed, thus also preventing the system from getting suspended. In the end what happens, is that the cancel_delayed_work_sync() in mmc_pm_notify() ends up waiting for mmc_rescan() to complete - and since mmc_rescan() wants to claim the host, it needs to wait for the I/O to be completed first. Typically, this problem is triggered in Android, if there is ongoing I/O while the user decides to suspend, resume and then suspend the system again. This due to that after the resume, an mmc_rescan() work gets punted to the workqueue, which job is to verify that the card remains inserted after the system has resumed. To fix this problem, userspace needs to become frozen to suspend the I/O, prior to turning off the card detection mechanism. Therefore, let's drop the PM notifiers for mmc subsystem altogether and rely on the card detection to be turned off/on as a part of the system_freezable_wq, that we are already using. Moreover, to allow and SDIO card to be removed during system suspend, let's manage this from a ->prepare() callback, assigned at the mmc_host_class level. In this way, we can use the parent device (the mmc_host_class device), to remove the card device that is the child, in the device_prepare() phase. Reported-by: Kiwoong Kim Cc: stable@vger.kernel.org # v4.5+ Signed-off-by: Ulf Hansson Reviewed-by: Linus Walleij Link: https://lore.kernel.org/r/20210310152900.149380-1-ulf.hansson@linaro.org Reviewed-by: Kiwoong Kim --- include/linux/mmc/host.h | 3 --- 1 file changed, 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index a001ad2f5f23..17d7b326af29 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -302,9 +302,6 @@ struct mmc_host { u32 ocr_avail_sdio; /* SDIO-specific OCR */ u32 ocr_avail_sd; /* SD-specific OCR */ u32 ocr_avail_mmc; /* MMC-specific OCR */ -#ifdef CONFIG_PM_SLEEP - struct notifier_block pm_notify; -#endif struct wakeup_source *ws; /* Enable consume of uevents */ u32 max_current_330; u32 max_current_300; -- cgit From 6dab809bb5b183015e19d558bfa95107de660be0 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Mon, 19 Apr 2021 14:24:55 +0300 Subject: mmc: core: Convert mmc_of_parse_voltage() to use device property API mmc_of_parse() for a few years has been using device property API. Convert mmc_of_parse_voltage() as well. At the same time switch users to new API. Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20210419112459.25241-2-andriy.shevchenko@linux.intel.com Signed-off-by: Ulf Hansson --- include/linux/mmc/host.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index 17d7b326af29..c7e7b43600e9 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -509,7 +509,7 @@ void mmc_free_host(struct mmc_host *); void mmc_of_parse_clk_phase(struct mmc_host *host, struct mmc_clk_phase_map *map); int mmc_of_parse(struct mmc_host *host); -int mmc_of_parse_voltage(struct device_node *np, u32 *mask); +int mmc_of_parse_voltage(struct mmc_host *host, u32 *mask); static inline void *mmc_priv(struct mmc_host *host) { -- cgit From edd602146507532c1714d8428f654b87205f492e Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Mon, 19 Apr 2021 14:24:59 +0300 Subject: mmc: mmc_spi: Make of_mmc_spi.c resource provider agnostic In order to use the same driver on non-OF platforms, make of_mmc_spi.c resource provider agnostic. Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20210419112459.25241-6-andriy.shevchenko@linux.intel.com Signed-off-by: Ulf Hansson --- include/linux/spi/mmc_spi.h | 9 --------- 1 file changed, 9 deletions(-) (limited to 'include/linux') diff --git a/include/linux/spi/mmc_spi.h b/include/linux/spi/mmc_spi.h index 778ae8eb1f3e..9ad9a06e488d 100644 --- a/include/linux/spi/mmc_spi.h +++ b/include/linux/spi/mmc_spi.h @@ -35,16 +35,7 @@ struct mmc_spi_platform_data { void (*setpower)(struct device *, unsigned int maskval); }; -#ifdef CONFIG_OF extern struct mmc_spi_platform_data *mmc_spi_get_pdata(struct spi_device *spi); extern void mmc_spi_put_pdata(struct spi_device *spi); -#else -static inline struct mmc_spi_platform_data * -mmc_spi_get_pdata(struct spi_device *spi) -{ - return spi->dev.platform_data; -} -static inline void mmc_spi_put_pdata(struct spi_device *spi) {} -#endif /* CONFIG_OF */ #endif /* __LINUX_SPI_MMC_SPI_H */ -- cgit