From 6cff59409b6d7f760fd0362f06c2dd6fba494759 Mon Sep 17 00:00:00 2001 From: Tobias Schramm Date: Fri, 30 Dec 2022 20:43:15 +0100 Subject: [PATCH] mmc: atmel-mci: fix race between stop command and start of next command [ Upstream commit 4db5609132c059b1a4d8fd4151a05f113530d2ae ] This commit fixes a race between completion of stop command and start of a new command. Previously the command ready interrupt was enabled before stop command was written to the command register. This caused the command ready interrupt to fire immediately since the CMDRDY flag is asserted constantly while there is no command in progress. Consequently the command state machine will immediately advance to the next state when the tasklet function is executed again, no matter actual completion state of the stop command. Thus a new command can then be dispatched immediately, interrupting and corrupting the stop command on the CMD line. Fix that by dropping the command ready interrupt enable before calling atmci_send_stop_cmd. atmci_send_stop_cmd does already enable the command ready interrupt, no further writes to ATMCI_IER are necessary. Signed-off-by: Tobias Schramm Acked-by: Ludovic Desroches Link: https://lore.kernel.org/r/20221230194315.809903-2-t.schramm@manjaro.org Signed-off-by: Ulf Hansson Signed-off-by: Sasha Levin --- drivers/mmc/host/atmel-mci.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c index bb9bbf1c927b6..dd18440a90c58 100644 --- a/drivers/mmc/host/atmel-mci.c +++ b/drivers/mmc/host/atmel-mci.c @@ -1817,7 +1817,6 @@ static void atmci_tasklet_func(struct tasklet_struct *t) atmci_writel(host, ATMCI_IER, ATMCI_NOTBUSY); state = STATE_WAITING_NOTBUSY; } else if (host->mrq->stop) { - atmci_writel(host, ATMCI_IER, ATMCI_CMDRDY); atmci_send_stop_cmd(host, data); state = STATE_SENDING_STOP; } else { @@ -1850,8 +1849,6 @@ static void atmci_tasklet_func(struct tasklet_struct *t) * command to send. */ if (host->mrq->stop) { - atmci_writel(host, ATMCI_IER, - ATMCI_CMDRDY); atmci_send_stop_cmd(host, data); state = STATE_SENDING_STOP; } else { -- 2.39.5