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? 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 >>>
