[PATCH] mailbox: mtk-cmdq: Do not request irq until we are ready

From: Ricardo Ribalda
Date: Fri Nov 25 2022 - 11:19:42 EST


If the system comes from kexec() the peripheral might trigger an IRQ
befoe we are ready for it. Triggering a crash due to an access to
invalid memory.

Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
---
To: Jassi Brar <jassisinghbrar@xxxxxxxxx>
To: Matthias Brugger <matthias.bgg@xxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-mediatek@xxxxxxxxxxxxxxxxxxx
---
drivers/mailbox/mtk-cmdq-mailbox.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/mailbox/mtk-cmdq-mailbox.c b/drivers/mailbox/mtk-cmdq-mailbox.c
index 9465f9081515..829f1ef3309f 100644
--- a/drivers/mailbox/mtk-cmdq-mailbox.c
+++ b/drivers/mailbox/mtk-cmdq-mailbox.c
@@ -545,12 +545,6 @@ static int cmdq_probe(struct platform_device *pdev)
cmdq->control_by_sw = plat_data->control_by_sw;
cmdq->gce_num = plat_data->gce_num;
cmdq->irq_mask = GENMASK(cmdq->thread_nr - 1, 0);
- err = devm_request_irq(dev, cmdq->irq, cmdq_irq_handler, IRQF_SHARED,
- "mtk_cmdq", cmdq);
- if (err < 0) {
- dev_err(dev, "failed to register ISR (%d)\n", err);
- return err;
- }

dev_dbg(dev, "cmdq device: addr:0x%p, va:0x%p, irq:%d\n",
dev, cmdq->base, cmdq->irq);
@@ -613,6 +607,13 @@ static int cmdq_probe(struct platform_device *pdev)

platform_set_drvdata(pdev, cmdq);

+ err = devm_request_irq(dev, cmdq->irq, cmdq_irq_handler, IRQF_SHARED,
+ "mtk_cmdq", cmdq);
+ if (err < 0) {
+ dev_err(dev, "failed to register ISR (%d)\n", err);
+ return err;
+ }
+
WARN_ON(clk_bulk_prepare(cmdq->gce_num, cmdq->clocks));

cmdq_init(cmdq);

---
base-commit: 4312098baf37ee17a8350725e6e0d0e8590252d4
change-id: 20221125-mtk-mailbox-ba6cbd1d91b6

Best regards,
--
Ricardo Ribalda <ribalda@xxxxxxxxxxxx>