From: Adam Young <admiyo@os•amperecomputing.com>
To: Sudeep Holla <sudeep.holla@kernel•org>,
Jassi Brar <jassisinghbrar@gmail•com>
Cc: linux-kernel@vger•kernel.org, linux-hwmon@vger•kernel.org,
"Rafael J . Wysocki" <rafael@kernel•org>,
Len Brown <lenb@kernel•org>,
linux-acpi@vger•kernel.org, Andi Shyti <andi.shyti@kernel•org>,
Guenter Roeck <linux@roeck-us•net>,
Huisong Li <lihuisong@huawei•com>,
MyungJoo Ham <myungjoo.ham@samsung•com>,
Kyungmin Park <kyungmin.park@samsung•com>,
Chanwoo Choi <cw00.choi@samsung•com>,
linux-arm-kernel@lists•infradead.org
Subject: [PATCH v02] mailbox: pcc: report errors for PCC clients
Date: Mon, 18 May 2026 15:30:06 -0400 [thread overview]
Message-ID: <20260518193006.27425-1-admiyo@os.amperecomputing.com> (raw)
The tx_done callback function has a return code (rc) parameter
that the tx_done callback can use to determine how to handle an error.
However the IRQ handler was not setting that value if there is an error.
The following clients are affected:
drivers/acpi/cppc_acpi.c
drivers/i2c/busses/i2c-xgene-slimpro.c
drivers/hwmon/xgene-hwmon.c
drivers/soc/hisilicon/kunpeng_hccs.c
drivers/devfreq/hisi_uncore_freq.c
All of these only use the error code to report, so they
are expecting an error code to come thorugh, but they
do not modify behavior based on this code.
In the case of an error code in the IRQ, the handler was returning
IRQ_NONE which is not correct: the IRQ handler was matched
to the IRQ. This mean that multiple error codes returned from
a PCC triggered interrupt would end up disabling the device.
In addition, if the error code IRQ was coming from a Type4 Device that was
expecting an IRQ response, that device would then be hung.
Fixes: c45ded7e1135 ("mailbox: pcc: Add support for PCCT extended PCC subspaces(type 3/4)")
Signed-off-by: Adam Young <admiyo@os•amperecomputing.com>
---
---
drivers/mailbox/pcc.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c
index 636879ae1db7..16b9ce087b9e 100644
--- a/drivers/mailbox/pcc.c
+++ b/drivers/mailbox/pcc.c
@@ -314,6 +314,7 @@ static irqreturn_t pcc_mbox_irq(int irq, void *p)
{
struct pcc_chan_info *pchan;
struct mbox_chan *chan = p;
+ int rc;
pchan = chan->con_priv;
@@ -327,8 +328,7 @@ static irqreturn_t pcc_mbox_irq(int irq, void *p)
if (!pcc_mbox_cmd_complete_check(pchan))
return IRQ_NONE;
- if (pcc_mbox_error_check_and_clear(pchan))
- return IRQ_NONE;
+ rc = pcc_mbox_error_check_and_clear(pchan);
/*
* Clear this flag after updating interrupt ack register and just
@@ -337,8 +337,9 @@ 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;
- mbox_chan_received_data(chan, NULL);
- mbox_chan_txdone(chan, 0);
+ if (!rc)
+ mbox_chan_received_data(chan, NULL);
+ mbox_chan_txdone(chan, rc);
pcc_chan_acknowledge(pchan);
--
2.43.0
next reply other threads:[~2026-05-18 19:30 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-18 19:30 Adam Young [this message]
2026-05-19 13:23 ` [PATCH v02] mailbox: pcc: report errors for PCC clients Sudeep Holla
2026-06-02 18:44 ` Adam Young
2026-06-03 15:15 ` Adam Young
2026-05-19 13:54 ` lihuisong (C)
2026-05-19 16:25 ` Sudeep Holla
2026-05-20 11:53 ` lihuisong (C)
2026-05-20 13:32 ` Sudeep Holla
2026-05-21 12:26 ` lihuisong (C)
2026-05-22 16:52 ` Adam Young
2026-05-26 3:53 ` lihuisong (C)
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