The original purpose of the code I fix is to replace max_discard with
max_trim if max_trim is less than max_discard. When max_discard is 0
we should replace max_discard with max_trim as well, because
max_discard equals 0 happens only when the max_do_calc_max_discard
process is overflowed, so if mmc_can_trim(card) is true, max_discard
should be replaced by an available max_trim.
However, in the original code, there are two lines of code interfere
the right process.
1) if (max_discard && mmc_can_trim(card))
when max_discard is 0, it skips the process checking if max_discard
needs to be replaced with max_trim.
2) if (max_trim < max_discard)
the condition is false when max_discard is 0. it also skips the process
that replaces max_discard with max_trim, in fact, we should replace the
0-valued max_discard with max_trim.

Signed-off-by: Jiong Wu <Lohengrin1024@gmail.com>
Fixes: b305882fbc87 (mmc: core: optimize mmc_calc_max_discard)
Cc: stable@vger.kernel.org # v4.17+
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

The busy timeout is 250msec per discard command.

Signed-off-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

SD spec v5.1 adds discard support. The flows and commands are similar to
mmc, so just set the discard arg in CMD38.

A host which supports DISCARD shall check if the DISCARD_SUPPORT (b313)
is set in the SD_STATUS register.  If the card does not support discard,
the host shall not issue DISCARD command, but ERASE command instead.

Post the DISCARD operation, the card may de-allocate the discarded
blocks partially or completely. So the host mustn't make any assumptions
concerning the content of the discarded region. This is unlike ERASE
command, in which the region is guaranteed to contain either '0's or
'1's, depends on the content of DATA_STAT_AFTER_ERASE (b55) in the scr
register.

One more important difference compared to ERASE is the busy timeout
which we will address on the next patch.

Signed-off-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

In case of CQHCI, mrq->cmd may be NULL for data requests (non DCMD).
In such case mmc_should_fail_request is directly dereferencing
mrq->cmd while cmd is NULL.
Fix this by checking for mrq->cmd pointer.

Fixes: 72a5af554df8 ("mmc: core: Add support for handling CQE requests")
Signed-off-by: Ritesh Harjani <riteshh@codeaurora.org>
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

The only user of mmc_align_data_size() is sdio_align_size(), which is
called from SDIO func drivers to let them distinguish, how to optimally
allocate data buffers.

Let's move mmc_align_data_size() close to the SDIO code as to make it
static, rename it to _sdio_align_size() and simplify its definition, all
with the purpose of clarifying that this is SDIO specific.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Avri Altman <avri.altman@wdc.com>

MMC OF parsing functions, which parses various host DT properties, should
stay close to each other. Therefore, let's move mmc_of_parse_voltage()
close to mmc_of_parse() into host.c.

Additionally, there is no reason to build the code only when CONFIG_OF is
set, as there should be stub functions for the OF helpers that is being
used, so let's drop this condition as well.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

The mmc regulator helper functions, are placed in the extensive core.c
file.  In a step towards trying to create a better structure of files,
avoiding too many lines of code per file, let's move these helpers to a new
file, regulator.c.

Moreover, this within this context it makes sense to also drop the export
of mmc_vddrange_to_ocrmask(), but instead let's make it internal to the mmc
core.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

In MMC, the discard arg is a read-only ext_csd parameter - set it once
on card init. To be consistent, do that for SD as well even though its
discard arg is always 0x0.

Signed-off-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

To allow mmc host drivers to inform the mmc core about rather using
pm_runtime_put_sync_suspend() instead of pm_runtime_put_autosuspend(),
let's introduce MMC_CAP_SYNC_RUNTIME_PM.

This is especially useful for those mmc host drivers that don't benefit
from using the runtime PM autosuspend feature. Typically this is those that
relies on parent devices to power the card via runtime PM, like some USB
host drivers for example.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>