[PATCH v30 1/3] mailbox: pcc: Type3 Buffer handles ACK IRQ
From: Adam Young <hidden>
Date: 2025-10-16 21:02:38
Also in:
lkml
Subsystem:
acpi pcc(platform communication channel) mailbox driver, mailbox api, the rest · Maintainers:
Sudeep Holla, Jassi Brar, Linus Torvalds
The PCC protocol type 3 requests include a field that indicates that the recipient should trigger an interrupt once the message has been read from the buffer. The sender uses this interrupt to know that a transmission is complete, and it is safe to send additional messages. Signed-off-by: Adam Young <redacted> mailbox/pcc extended memory helper functions --- drivers/mailbox/pcc.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+)
diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c
index f6714c233f5a..978a7b674946 100644
--- a/drivers/mailbox/pcc.c
+++ b/drivers/mailbox/pcc.c@@ -306,6 +306,18 @@ static void pcc_chan_acknowledge(struct pcc_chan_info *pchan) pcc_chan_reg_read_modify_write(&pchan->db); } +static bool pcc_last_tx_done(struct mbox_chan *chan) +{ + struct pcc_chan_info *pchan = chan->con_priv; + u64 val; + + pcc_chan_reg_read(&pchan->cmd_complete, &val); + if (!val) + return false; + else + return true; +} + /** * pcc_mbox_irq - PCC mailbox interrupt handler * @irq: interrupt number
@@ -340,6 +352,14 @@ static irqreturn_t pcc_mbox_irq(int irq, void *p) * required to avoid any possible race in updatation of this flag. */ pchan->chan_in_use = false; + + /** + * The remote side sent an ack. + */ + if (pchan->type == ACPI_PCCT_TYPE_EXT_PCC_MASTER_SUBSPACE && + chan->active_req) + mbox_chan_txdone(chan, 0); + mbox_chan_received_data(chan, NULL); pcc_chan_acknowledge(pchan);
@@ -490,6 +510,7 @@ static const struct mbox_chan_ops pcc_chan_ops = { .send_data = pcc_send_data, .startup = pcc_startup, .shutdown = pcc_shutdown, + .last_tx_done = pcc_last_tx_done, }; /**
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2.43.0