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authorPhil Elwell <phil@raspberrypi.org>2018-11-11 21:23:54 +0100
committerUlf Hansson <ulf.hansson@linaro.org>2018-12-17 08:26:24 +0100
commit07d405769afea5718529fc9e341f0b13b3189b6f (patch)
tree2bb61491884fe35eb2c67e837bd4965df6bf5118
parentf6000a4eb34e6462bc0dd39809c1bb99f9633269 (diff)
mmc: bcm2835: Recover from MMC_SEND_EXT_CSD
If the user issues an "mmc extcsd read", the SD controller receives what it thinks is a SEND_IF_COND command with an unexpected data block. The resulting operations leave the FSM stuck in READWAIT, a state which persists until the MMC framework resets the controller, by which point the root filesystem is likely to have been unmounted. A less heavyweight solution is to detect the condition and nudge the FSM by asserting the (self-clearing) FORCE_DATA_MODE bit. Link: https://github.com/raspberrypi/linux/issues/2728 Signed-off-by: Phil Elwell <phil@raspberrypi.org> Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> Acked-by: Eric Anholt <eric@anholt.net> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
-rw-r--r--drivers/mmc/host/bcm2835.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/mmc/host/bcm2835.c b/drivers/mmc/host/bcm2835.c
index beec8d01fabc..096e737dffaa 100644
--- a/drivers/mmc/host/bcm2835.c
+++ b/drivers/mmc/host/bcm2835.c
@@ -762,6 +762,8 @@ static void bcm2835_finish_command(struct bcm2835_host *host)
if (!(sdhsts & SDHSTS_CRC7_ERROR) ||
(host->cmd->opcode != MMC_SEND_OP_COND)) {
+ u32 edm, fsm;
+
if (sdhsts & SDHSTS_CMD_TIME_OUT) {
host->cmd->error = -ETIMEDOUT;
} else {
@@ -770,6 +772,13 @@ static void bcm2835_finish_command(struct bcm2835_host *host)
bcm2835_dumpregs(host);
host->cmd->error = -EILSEQ;
}
+ edm = readl(host->ioaddr + SDEDM);
+ fsm = edm & SDEDM_FSM_MASK;
+ if (fsm == SDEDM_FSM_READWAIT ||
+ fsm == SDEDM_FSM_WRITESTART1)
+ /* Kick the FSM out of its wait */
+ writel(edm | SDEDM_FORCE_DATA_MODE,
+ host->ioaddr + SDEDM);
bcm2835_finish_request(host);
return;
}