mmc: core: Allow host controllers to require R1B for CMD6

[ Upstream commit 1292e3efb149ee21d8d33d725eeed4e6b1ade963 ]

It has turned out that some host controllers can't use R1B for CMD6 and
other commands that have R1B associated with them. Therefore invent a new
host cap, MMC_CAP_NEED_RSP_BUSY to let them specify this.

In __mmc_switch(), let's check the flag and use it to prevent R1B responses
from being converted into R1. Note that, this also means that the host are
on its own, when it comes to manage the busy timeout.

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
index 873b2aa0c155623f60a0a30374e2174d39e5da29..693b99eff74b5c28529fa18021eec666ba2fd068 100644 (file)
--- a/drivers/mmc/core/mmc_ops.c
+++ b/drivers/mmc/core/mmc_ops.c
@@ -536,10 +536,12 @@ int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value,
         * If the cmd timeout and the max_busy_timeout of the host are both
         * specified, let's validate them. A failure means we need to prevent
         * the host from doing hw busy detection, which is done by converting
-        * to a R1 response instead of a R1B.
+        * to a R1 response instead of a R1B. Note, some hosts requires R1B,
+        * which also means they are on their own when it comes to deal with the
+        * busy timeout.
         */
-       if (timeout_ms && host->max_busy_timeout &&
-               (timeout_ms > host->max_busy_timeout))
+       if (!(host->caps & MMC_CAP_NEED_RSP_BUSY) && timeout_ms &&
+           host->max_busy_timeout && (timeout_ms > host->max_busy_timeout))
                use_r1b_resp = false;
 
        cmd.opcode = MMC_SWITCH;

diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 840462ed1ec7e41d2b8c1d066cae0e7b5e29bd10..7e8e5b20e82b06085f22e3c0813d3369f93cce64 100644 (file)
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -332,6 +332,7 @@ struct mmc_host {
                                 MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR104 | \
                                 MMC_CAP_UHS_DDR50)
 /* (1 << 21) is free for reuse */
+#define MMC_CAP_NEED_RSP_BUSY  (1 << 22)       /* Commands with R1B can't use R1. */
 #define MMC_CAP_DRIVER_TYPE_A  (1 << 23)       /* Host supports Driver Type A */
 #define MMC_CAP_DRIVER_TYPE_C  (1 << 24)       /* Host supports Driver Type C */
 #define MMC_CAP_DRIVER_TYPE_D  (1 << 25)       /* Host supports Driver Type D */