mmc: core: Respect MMC_CAP_NEED_RSP_BUSY for erase/trim/discard

The busy timeout that is computed for each erase/trim/discard operation,
can become quite long and may thus exceed the host->max_busy_timeout. If
that becomes the case, mmc_do_erase() converts from using an R1B response
to an R1 response, as to prevent the host from doing HW busy detection.

However, it has turned out that some hosts requires an R1B response no
matter what, so let's respect that via checking MMC_CAP_NEED_RSP_BUSY. Note
that, if the R1B gets enforced, the host becomes fully responsible of
managing the needed busy timeout, in one way or the other.

Suggested-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Cc: <stable@vger.kernel.org>
Tested-by: Anders Roxell <anders.roxell@linaro.org>
Tested-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Tested-by: Faiz Abbas <faiz_abbas@ti.com>
Tested-By: Peter Geis <pgwipeout@gmail.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index aa54d359dab74beb7ea27850b5ac144511df3fdc..a971c4bcc442b11ab76c5425bbab46c89bf32dfd 100644 (file)
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1732,8 +1732,11 @@ static int mmc_do_erase(struct mmc_card *card, unsigned int from,
         * the erase operation does not exceed the max_busy_timeout, we should
         * use R1B response. Or we need to prevent the host from doing hw busy
         * detection, which is done by converting to a R1 response instead.
+        * Note, some hosts requires R1B, which also means they are on their own
+        * when it comes to deal with the busy timeout.
         */
-       if (card->host->max_busy_timeout &&
+       if (!(card->host->caps & MMC_CAP_NEED_RSP_BUSY) &&
+           card->host->max_busy_timeout &&
            busy_timeout > card->host->max_busy_timeout) {
                cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
        } else {