On Tue, 2 Jun 2020 at 19:31, Corey Gao <gaoce123@xxxxxxxxx> wrote: > > If __mmc_start_req(host, mrq) fails with error, the mrq->cmd->mrq will > be NULL. This will cause kernel panic in the following > mmc_wait_for_req_done(host, mrq). Add error check to cancle unnecessary > mmc_wait_for_req_done(host, mrq) if __mmc_start_req(host, mrq) fails. The above is a bit hard for me to follow, can you please try to elaborate on the problem. Moreover, please, provide a stack trace, as that is easier to follow for me. Kind regards Uffe > > Signed-off-by: Corey Gao <gaoce123@xxxxxxxxx> > --- > drivers/mmc/core/core.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c > index 2553d903a82b..b13b484e64aa 100644 > --- a/drivers/mmc/core/core.c > +++ b/drivers/mmc/core/core.c > @@ -734,9 +734,11 @@ EXPORT_SYMBOL(mmc_start_req); > */ > void mmc_wait_for_req(struct mmc_host *host, struct mmc_request *mrq) > { > - __mmc_start_req(host, mrq); > + int err; > > - if (!mrq->cap_cmd_during_tfr) > + err = __mmc_start_req(host, mrq); > + > + if (!mrq->cap_cmd_during_tfr && !err) > mmc_wait_for_req_done(host, mrq); > } > EXPORT_SYMBOL(mmc_wait_for_req); > -- > 2.17.1 >