diff options
Diffstat (limited to 'drivers/firmware/arm_scmi/transports/mailbox.c')
| -rw-r--r-- | drivers/firmware/arm_scmi/transports/mailbox.c | 32 |
1 files changed, 21 insertions, 11 deletions
diff --git a/drivers/firmware/arm_scmi/transports/mailbox.c b/drivers/firmware/arm_scmi/transports/mailbox.c index 1a754dee24f7..e3d5f7560990 100644 --- a/drivers/firmware/arm_scmi/transports/mailbox.c +++ b/drivers/firmware/arm_scmi/transports/mailbox.c @@ -25,6 +25,7 @@ * @chan_platform_receiver: Optional Platform Receiver mailbox unidirectional channel * @cinfo: SCMI channel info * @shmem: Transmit/Receive shared memory area + * @chan_lock: Lock that prevents multiple xfers from being queued */ struct scmi_mailbox { struct mbox_client cl; @@ -33,6 +34,7 @@ struct scmi_mailbox { struct mbox_chan *chan_platform_receiver; struct scmi_chan_info *cinfo; struct scmi_shared_mem __iomem *shmem; + struct mutex chan_lock; }; #define client_to_scmi_mailbox(c) container_of(c, struct scmi_mailbox, cl) @@ -238,6 +240,7 @@ static int mailbox_chan_setup(struct scmi_chan_info *cinfo, struct device *dev, cinfo->transport_info = smbox; smbox->cinfo = cinfo; + mutex_init(&smbox->chan_lock); return 0; } @@ -267,13 +270,23 @@ static int mailbox_send_message(struct scmi_chan_info *cinfo, struct scmi_mailbox *smbox = cinfo->transport_info; int ret; - ret = mbox_send_message(smbox->chan, xfer); + /* + * The mailbox layer has its own queue. However the mailbox queue + * confuses the per message SCMI timeouts since the clock starts when + * the message is submitted into the mailbox queue. So when multiple + * messages are queued up the clock starts on all messages instead of + * only the one inflight. + */ + mutex_lock(&smbox->chan_lock); - /* mbox_send_message returns non-negative value on success, so reset */ - if (ret > 0) - ret = 0; + ret = mbox_send_message(smbox->chan, xfer); + /* mbox_send_message returns non-negative value on success */ + if (ret < 0) { + mutex_unlock(&smbox->chan_lock); + return ret; + } - return ret; + return 0; } static void mailbox_mark_txdone(struct scmi_chan_info *cinfo, int ret, @@ -281,13 +294,10 @@ static void mailbox_mark_txdone(struct scmi_chan_info *cinfo, int ret, { struct scmi_mailbox *smbox = cinfo->transport_info; - /* - * NOTE: we might prefer not to need the mailbox ticker to manage the - * transfer queueing since the protocol layer queues things by itself. - * Unfortunately, we have to kick the mailbox framework after we have - * received our message. - */ mbox_client_txdone(smbox->chan, ret); + + /* Release channel */ + mutex_unlock(&smbox->chan_lock); } static void mailbox_fetch_response(struct scmi_chan_info *cinfo, |