Re: [PATCH 3/6] mailbox: pcc: Set txdone_irq/txdone_poll based on PCCT flags
From: Adam Young
Date: Fri Oct 17 2025 - 13:19:52 EST
Tested-by: Adam Young <admiyo@xxxxxxxxxxxxxxxxxxxxxx>
On 10/16/25 15:08, Sudeep Holla wrote:
The PCC controller currently enables txdone via IRQ if the PCCT exposes
platform capability to generate command completion interrupt, but it
leaves txdone_poll unchanged. Make the behaviour explicit:
- If ACPI_PCCT_DOORBELL is present, use txdone_irq and disable polling.
- Otherwise, disable txdone_irq and fall back to txdone_poll.
Configure the PCC mailbox to use interrupt-based completion for PCC types
that signal completion via IRQ using TXDONE_BY_IRQ, and fall back to
polling for others using TXDONE_BY_POLL.
This ensures the PCC driver uses the appropriate completion mechanism
according to the PCCT table definition and makes the completion mode
unambiguous avoiding mixed signalling when the platform lacks a doorbell
flag set.
Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
---
drivers/mailbox/pcc.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c
index 2b690c268cf0..327e022973db 100644
--- a/drivers/mailbox/pcc.c
+++ b/drivers/mailbox/pcc.c
@@ -791,8 +791,13 @@ static int pcc_mbox_probe(struct platform_device *pdev)
(unsigned long) pcct_tbl + sizeof(struct acpi_table_pcct));
acpi_pcct_tbl = (struct acpi_table_pcct *) pcct_tbl;
- if (acpi_pcct_tbl->flags & ACPI_PCCT_DOORBELL)
+ if (acpi_pcct_tbl->flags & ACPI_PCCT_DOORBELL) {
pcc_mbox_ctrl->txdone_irq = true;
+ pcc_mbox_ctrl->txdone_poll = false;
+ } else {
+ pcc_mbox_ctrl->txdone_irq = false;
+ pcc_mbox_ctrl->txdone_poll = true;
+ }
for (i = 0; i < count; i++) {
struct pcc_chan_info *pchan = chan_info + i;