[PATCH AUTOSEL 5.4 06/33] mmc: mediatek: fix race condition between msdc_request_timeout and irq
From: Sasha Levin <sashal@kernel.org>
Date: 2021-03-02 16:29:40
Also in:
linux-arm-kernel, linux-mediatek, linux-mmc, lkml
Subsystem:
mediatek mmc/sd/sdio driver, multimedia card (mmc), secure digital (sd) and sdio subsystem, the rest · Maintainers:
Chaotian Jing, Ulf Hansson, Linus Torvalds
From: Chaotian Jing <chaotian.jing@mediatek.com> [ Upstream commit 0354ca6edd464a2cf332f390581977b8699ed081 ] when get request SW timeout, if CMD/DAT xfer done irq coming right now, then there is race between the msdc_request_timeout work and irq handler, and the host->cmd and host->data may set to NULL in irq handler. also, current flow ensure that only one path can go to msdc_request_done(), so no need check the return value of cancel_delayed_work(). Signed-off-by: Chaotian Jing <chaotian.jing@mediatek.com> Link: https://lore.kernel.org/r/20201218071611.12276-1-chaotian.jing@mediatek.com (local) Signed-off-by: Ulf Hansson <redacted> Signed-off-by: Sasha Levin <sashal@kernel.org> --- drivers/mmc/host/mtk-sd.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-)
diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
index 9d47a2bd2546..1254a5650cff 100644
--- a/drivers/mmc/host/mtk-sd.c
+++ b/drivers/mmc/host/mtk-sd.c@@ -1020,13 +1020,13 @@ static void msdc_track_cmd_data(struct msdc_host *host, static void msdc_request_done(struct msdc_host *host, struct mmc_request *mrq) { unsigned long flags; - bool ret; - ret = cancel_delayed_work(&host->req_timeout); - if (!ret) { - /* delay work already running */ - return; - } + /* + * No need check the return value of cancel_delayed_work, as only ONE + * path will go here! + */ + cancel_delayed_work(&host->req_timeout); + spin_lock_irqsave(&host->lock, flags); host->mrq = NULL; spin_unlock_irqrestore(&host->lock, flags);
@@ -1046,7 +1046,7 @@ static bool msdc_cmd_done(struct msdc_host *host, int events, bool done = false; bool sbc_error; unsigned long flags; - u32 *rsp = cmd->resp; + u32 *rsp; if (mrq->sbc && cmd == mrq->cmd && (events & (MSDC_INT_ACMDRDY | MSDC_INT_ACMDCRCERR
@@ -1067,6 +1067,7 @@ static bool msdc_cmd_done(struct msdc_host *host, int events, if (done) return true; + rsp = cmd->resp; sdr_clr_bits(host->base + MSDC_INTEN, cmd_ints_mask);
@@ -1254,7 +1255,7 @@ static void msdc_data_xfer_next(struct msdc_host *host, static bool msdc_data_xfer_done(struct msdc_host *host, u32 events, struct mmc_request *mrq, struct mmc_data *data) { - struct mmc_command *stop = data->stop; + struct mmc_command *stop; unsigned long flags; bool done; unsigned int check_data = events &
@@ -1270,6 +1271,7 @@ static bool msdc_data_xfer_done(struct msdc_host *host, u32 events, if (done) return true; + stop = data->stop; if (check_data || (stop && stop->error)) { dev_dbg(host->dev, "DMA status: 0x%8X\n",
--
2.30.1