Hello Bjorn, On 5/28/21 5:26 AM, Bjorn Andersson wrote: > On Tue 20 Apr 04:19 CDT 2021, Arnaud Pouliquen wrote: > >> mbox_send_message is called by passing a local dummy message or >> a function parameter. As the message is queued, it is dereferenced. >> This works because the message field is not used by the stm32 ipcc >> driver, but it is not clean. >> >> Fix by passing a constant string in all cases. >> >> The associated comments are removed because rproc should not have to >> deal with the behavior of the mailbox frame. >> > > Didn't we conclude that the mailbox driver doesn't actually dereference > the pointer being passed? Right it can store the reference to queue the sent. > > If so I would prefer that you just pass NULL, so that if you in the > future need to pass some actual data it will be easy to distinguish the > old and new case. I can not use NULL pointer in stm32_rproc_attach and stm32_rproc_detach case. The reason is that the tx_done callback is not called if the message is NULL. (https://elixir.bootlin.com/linux/latest/source/drivers/mailbox/mailbox.c#L106) I could use NULL pointer in stm32_rproc_kick, but I would prefer to use the same way of calling mbox_send_message for all use cases and not take into account the mailbox internal behavior. Thanks, Arnaud > > Regards, > Bjorn > >> Reported-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx> >> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxxxxxxx> >> --- >> drivers/remoteproc/stm32_rproc.c | 14 +++++--------- >> 1 file changed, 5 insertions(+), 9 deletions(-) >> >> diff --git a/drivers/remoteproc/stm32_rproc.c b/drivers/remoteproc/stm32_rproc.c >> index 7353f9e7e7af..0e8203a432ab 100644 >> --- a/drivers/remoteproc/stm32_rproc.c >> +++ b/drivers/remoteproc/stm32_rproc.c >> @@ -474,14 +474,12 @@ static int stm32_rproc_attach(struct rproc *rproc) >> static int stm32_rproc_detach(struct rproc *rproc) >> { >> struct stm32_rproc *ddata = rproc->priv; >> - int err, dummy_data, idx; >> + int err, idx; >> >> /* Inform the remote processor of the detach */ >> idx = stm32_rproc_mbox_idx(rproc, STM32_MBX_DETACH); >> if (idx >= 0 && ddata->mb[idx].chan) { >> - /* A dummy data is sent to allow to block on transmit */ >> - err = mbox_send_message(ddata->mb[idx].chan, >> - &dummy_data); >> + err = mbox_send_message(ddata->mb[idx].chan, "stop"); >> if (err < 0) >> dev_warn(&rproc->dev, "warning: remote FW detach without ack\n"); >> } >> @@ -493,15 +491,13 @@ static int stm32_rproc_detach(struct rproc *rproc) >> static int stm32_rproc_stop(struct rproc *rproc) >> { >> struct stm32_rproc *ddata = rproc->priv; >> - int err, dummy_data, idx; >> + int err, idx; >> >> /* request shutdown of the remote processor */ >> if (rproc->state != RPROC_OFFLINE) { >> idx = stm32_rproc_mbox_idx(rproc, STM32_MBX_SHUTDOWN); >> if (idx >= 0 && ddata->mb[idx].chan) { >> - /* a dummy data is sent to allow to block on transmit */ >> - err = mbox_send_message(ddata->mb[idx].chan, >> - &dummy_data); >> + err = mbox_send_message(ddata->mb[idx].chan, "detach"); >> if (err < 0) >> dev_warn(&rproc->dev, "warning: remote FW shutdown without ack\n"); >> } >> @@ -556,7 +552,7 @@ static void stm32_rproc_kick(struct rproc *rproc, int vqid) >> continue; >> if (!ddata->mb[i].chan) >> return; >> - err = mbox_send_message(ddata->mb[i].chan, (void *)(long)vqid); >> + err = mbox_send_message(ddata->mb[i].chan, "kick"); >> if (err < 0) >> dev_err(&rproc->dev, "%s: failed (%s, err:%d)\n", >> __func__, ddata->mb[i].name, err); >> -- >> 2.17.1 >>
