On Tue 22 Jun 02:56 CDT 2021, Arnaud POULIQUEN wrote: > Hello Bjorn > > On 5/28/21 10:03 AM, Arnaud POULIQUEN wrote: > > 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. > > Do you still have any concern about this patch? > I think my concern is now directed at the mailbox api. I think the change is reasonable given that. Thanks for the explanation. I'm picking up the patch. Regards, Bjorn > Thanks, > Arnaud > > > > > 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 > >>>
