linux-dev/drivers/mmc/core/host.c, branch linus/master

mmc: core: Drop HS400 caps unless 8-bit bus is supported too

2022-03-15T09:25:21Z

When mmc_select_hs400es() tries to switch to the HS400 ES mode, it may bail out early if the host doesn't support an 8-bit buswidth, as it's required for the HS400 mode. To improve the situation, let's instead drop the HS400 bits from the capability field if the 8-bit bus isn't supported. In this way, we allow the mmc initialization to continue by trying a lower speed mode. Signed-off-by: Ulf Hansson Link: https://lore.kernel.org/r/20220303165151.129806-1-ulf.hansson@linaro.org

mmc: host: Return an error when ->enable_sdio_irq() ops is missing

2022-03-15T09:25:21Z

Even if the current WARN() notifies the user that something is severely wrong, we can still end up in a PANIC() when trying to invoke the missing ->enable_sdio_irq() ops. Therefore, let's also return an error code and prevent the host from being added. While at it, move the code into a separate function to prepare for subsequent changes and for further host caps validations. Signed-off-by: Ulf Hansson Link: https://lore.kernel.org/r/20220303165142.129745-1-ulf.hansson@linaro.org

mmc: core: Disable card detect during shutdown

2021-12-20T10:09:15Z

It's seems prone to problems by allowing card detect and its corresponding mmc_rescan() work to run, during platform shutdown. For example, we may end up turning off the power while initializing a card, which potentially could damage it. To avoid this scenario, let's add ->shutdown_pre() callback for the mmc host class device and then turn of the card detect from there. Reported-by: Al Cooper Suggested-by: Adrian Hunter Signed-off-by: Ulf Hansson Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20211203141555.105351-1-ulf.hansson@linaro.org

mmc: host: factor out clearing the retune state

2021-08-24T08:15:28Z

We have this in two places, so let's have a dedicated function. It is also more readable. Signed-off-by: Wolfram Sang Acked-by: Adrian Hunter Reviewed-by: Yoshihiro Shimoda Tested-by: Yoshihiro Shimoda Link: https://lore.kernel.org/r/20210624151616.38770-4-wsa+renesas@sang-engineering.com Signed-off-by: Ulf Hansson

mmc: host: add kdoc for mmc_retune_{en|dis}able

2021-08-24T08:15:28Z

I wanted to use it in a wrong way, so document the intended way. Signed-off-by: Wolfram Sang Acked-by: Adrian Hunter Reviewed-by: Yoshihiro Shimoda Tested-by: Yoshihiro Shimoda Link: https://lore.kernel.org/r/20210624151616.38770-3-wsa+renesas@sang-engineering.com Signed-off-by: Ulf Hansson

mmc: core: Don't allocate IDA for OF aliases

2021-07-14T16:55:28Z

There's a chance that the IDA allocated in mmc_alloc_host() is not freed for some time because it's freed as part of a class' release function (see mmc_host_classdev_release() where the IDA is freed). If another thread is holding a reference to the class, then only once all balancing device_put() calls (in turn calling kobject_put()) have been made will the IDA be released and usable again. Normally this isn't a problem because the kobject is released before anything else that may want to use the same number tries to again, but with CONFIG_DEBUG_KOBJECT_RELEASE=y and OF aliases it becomes pretty easy to try to allocate an alias from the IDA twice while the first time it was allocated is still pending a call to ida_simple_remove(). It's also possible to trigger it by using CONFIG_DEBUG_KOBJECT_RELEASE and probe defering a driver at boot that calls mmc_alloc_host() before trying to get resources that may defer likes clks or regulators. Instead of allocating from the IDA in this scenario, let's just skip it if we know this is an OF alias. The number is already "claimed" and devices that aren't using OF aliases won't try to use the claimed numbers anyway (see mmc_first_nonreserved_index()). This should avoid any issues with mmc_alloc_host() returning failures from the ida_simple_get() in the case that we're using an OF alias. Cc: Matthias Schiffer Cc: Sujit Kautkar Reported-by: Zubin Mithra Fixes: fa2d0aa96941 ("mmc: core: Allow setting slot index via device tree alias") Signed-off-by: Stephen Boyd Link: https://lore.kernel.org/r/20210623075002.1746924-3-swboyd@chromium.org Cc: stable@vger.kernel.org Signed-off-by: Ulf Hansson

mmc: core: add support for disabling HS400 mode via DT

2021-06-14T11:57:39Z

On some boards the data strobe line isn't wired up, rendering HS400 support broken, even if both the controller and the eMMC claim to support it. Allow to disable HS400 mode via DT. Signed-off-by: Lucas Stach Link: https://lore.kernel.org/r/20210510190400.105162-3-l.stach@pengutronix.de Signed-off-by: Ulf Hansson

mmc: core: Convert mmc_of_parse_voltage() to use device property API

2021-04-23T07:29:49Z

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

mmc: core: Correct descriptions in mmc_of_parse()

2021-04-23T07:29:48Z

Since it has been converted to use device property API, the function and field descriptions become outdated. Correct them. Fixes: 73a47a9bb3e2 ("mmc: core: Use device_property_read instead of of_property_read") Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20210419112459.25241-1-andriy.shevchenko@linux.intel.com Signed-off-by: Ulf Hansson

mmc: core: Fix hanging on I/O during system suspend for removable cards

2021-03-30T09:42:03Z

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