[PATCH v2 06/13] mailbox: pcc: Refactor error handling in irq handler into separate function

Sudeep Holla
2025-03-05T16:39:07Z

The existing error handling logic in pcc_mbox_irq() is intermixed with the
main flow of the function. The command complete check and the complete
complete update/acknowledgment are nicely factored into separate functions.

Moves error detection and clearing logic into a separate function called:
pcc_mbox_error_check_and_clear() by extracting error-handling logic from
pcc_mbox_irq().

This ensures error checking and clearing are handled separately and it
improves maintainability by keeping the IRQ handler focused on processing
events.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
---
drivers/mailbox/pcc.c | 30 ++++++++++++++++++++----------
1 file changed, 20 insertions(+), 10 deletions(-)

diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c
index b1b8223b5da7002fc522523dbc82f6124215439a..41bd14851216e8c4f03052c81aaf938a5e5c5343 100644
--- a/drivers/mailbox/pcc.c
+++ b/drivers/mailbox/pcc.c
@@ -269,6 +269,25 @@ static bool pcc_mbox_cmd_complete_check(struct pcc_chan_info *pchan)
return !!val;
}

+static int pcc_mbox_error_check_and_clear(struct pcc_chan_info *pchan)
+{
+ u64 val;
+ int ret;
+
+ ret = pcc_chan_reg_read(&pchan->error, &val);
+ if (ret)
+ return ret;
+
+ val &= pchan->error.status_mask;
+ if (val) {
+ val &= ~pchan->error.status_mask;
+ pcc_chan_reg_write(&pchan->error, val);
+ return -EIO;
+ }
+
+ return 0;
+}
+
static void check_and_ack(struct pcc_chan_info *pchan, struct mbox_chan *chan)
{
struct acpi_pcct_ext_pcc_shared_memory pcc_hdr;
@@ -309,8 +328,6 @@ static irqreturn_t pcc_mbox_irq(int irq, void *p)
{
struct pcc_chan_info *pchan;
struct mbox_chan *chan = p;
- u64 val;
- int ret;

pchan = chan->con_priv;

@@ -324,15 +341,8 @@ static irqreturn_t pcc_mbox_irq(int irq, void *p)
if (!pcc_mbox_cmd_complete_check(pchan))
return IRQ_NONE;

- ret = pcc_chan_reg_read(&pchan->error, &val);
- if (ret)
+ if (pcc_mbox_error_check_and_clear(pchan))
return IRQ_NONE;
- val &= pchan->error.status_mask;
- if (val) {
- val &= ~pchan->error.status_mask;
- pcc_chan_reg_write(&pchan->error, val);
- return IRQ_NONE;
- }

/*
* Clear this flag immediately after updating interrupt ack register

--
2.34.1