| Message ID | 20201218071611.12276-1-chaotian.jing@mediatek.com |
|---|---|
| State | New |
| Headers | show |
| Series | mmc: mediatek: fix race condition between msdc_request_timeout and irq | expand |
On Fri, 18 Dec 2020 at 08:16, Chaotian Jing <chaotian.jing@mediatek.com> wrote: > > 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> Applied for next, thanks! Kind regards Uffe > --- > 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 de09c6347524..898ed1b023df 100644 > --- a/drivers/mmc/host/mtk-sd.c > +++ b/drivers/mmc/host/mtk-sd.c > @@ -1127,13 +1127,13 @@ 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); > @@ -1155,7 +1155,7 @@ 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 > @@ -1176,6 +1176,7 @@ 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); > > @@ -1363,7 +1364,7 @@ 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 & > @@ -1379,6 +1380,7 @@ 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", > -- > 2.18.0 >
diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c index de09c6347524..898ed1b023df 100644 --- a/drivers/mmc/host/mtk-sd.c +++ b/drivers/mmc/host/mtk-sd.c @@ -1127,13 +1127,13 @@ 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); @@ -1155,7 +1155,7 @@ 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 @@ -1176,6 +1176,7 @@ 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); @@ -1363,7 +1364,7 @@ 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 & @@ -1379,6 +1380,7 @@ 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",
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> --- drivers/mmc/host/mtk-sd.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-)