linux.git/drivers/mmc/core/host.c, branch v6.0

mmc: core: Do not evaluate HS400 capabilities if bus has no MMC capability

2022-07-12T10:25:38+00:00

If 'no-mmc' is set but 'no-mmc-hs400' is not, this warning is raised.
Specifying 'no-mmc' should be enough though.

Signed-off-by: Alexander Stein 
Link: https://lore.kernel.org/r/20220614113905.1458715-1-alexander.stein@ew.tq-group.com
Signed-off-by: Ulf Hansson

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

2022-03-15T09:25:21+00:00

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

2022-03-15T09:25:21+00:00

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

2021-12-20T10:09:15+00:00

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

2021-08-24T08:15:28+00:00

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

2021-08-24T08:15:28+00:00

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

2021-07-14T16:55:28+00:00

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

2021-06-14T11:57:39+00:00

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

2021-04-23T07:29:49+00:00

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()

2021-04-23T07:29:48+00:00

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