This is a note to let you know that I've just added the patch titled
mailbox: mpfs: switch to txdone_poll
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mailbox-mpfs-switch-to-txdone_poll.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit c74d098f4f9af9f738b79496cf22704dcb0726da
Author: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
Date: Tue Mar 7 20:22:52 2023 +0000
mailbox: mpfs: switch to txdone_poll
[ Upstream commit b5984a9844fc45cd301a28fb56f3de95f7e20f3c ]
The system controller on PolarFire SoC has no interrupt to signify that
the TX has been completed. The interrupt instead signals that a service
requested by the mailbox client has succeeded. If a service fails, there
will be no interrupt delivered.
Switch to polling the busy register to determine whether transmission
has completed.
Fixes: 83d7b1560810 ("mbox: add polarfire soc system controller mailbox")
Acked-by: Jassi Brar <jaswinder.singh@xxxxxxxxxx>
Tested-by: Valentina Fernandez <valentina.fernandezalanis@xxxxxxxxxxxxx>
Signed-off-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/mailbox/mailbox-mpfs.c b/drivers/mailbox/mailbox-mpfs.c
index 853901acaeec2..08aa840cccaca 100644
--- a/drivers/mailbox/mailbox-mpfs.c
+++ b/drivers/mailbox/mailbox-mpfs.c
@@ -79,6 +79,13 @@ static bool mpfs_mbox_busy(struct mpfs_mbox *mbox)
return status & SCB_STATUS_BUSY_MASK;
}
+static bool mpfs_mbox_last_tx_done(struct mbox_chan *chan)
+{
+ struct mpfs_mbox *mbox = (struct mpfs_mbox *)chan->con_priv;
+
+ return !mpfs_mbox_busy(mbox);
+}
+
static int mpfs_mbox_send_data(struct mbox_chan *chan, void *data)
{
struct mpfs_mbox *mbox = (struct mpfs_mbox *)chan->con_priv;
@@ -182,7 +189,6 @@ static irqreturn_t mpfs_mbox_inbox_isr(int irq, void *data)
mpfs_mbox_rx_data(chan);
- mbox_chan_txdone(chan, 0);
return IRQ_HANDLED;
}
@@ -212,6 +218,7 @@ static const struct mbox_chan_ops mpfs_mbox_ops = {
.send_data = mpfs_mbox_send_data,
.startup = mpfs_mbox_startup,
.shutdown = mpfs_mbox_shutdown,
+ .last_tx_done = mpfs_mbox_last_tx_done,
};
static int mpfs_mbox_probe(struct platform_device *pdev)
@@ -247,7 +254,8 @@ static int mpfs_mbox_probe(struct platform_device *pdev)
mbox->controller.num_chans = 1;
mbox->controller.chans = mbox->chans;
mbox->controller.ops = &mpfs_mbox_ops;
- mbox->controller.txdone_irq = true;
+ mbox->controller.txdone_poll = true;
+ mbox->controller.txpoll_period = 10u;
ret = devm_mbox_controller_register(&pdev->dev, &mbox->controller);
if (ret) {
