[PATCH v3] mailbox: mtk-cmdq: Do not request irq until we are ready

From: Ricardo Ribalda
Date: Wed Nov 30 2022 - 07:58:56 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: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
To: Jassi Brar <jassisinghbrar@xxxxxxxxx>
To: Matthias Brugger <matthias.bgg@xxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-mediatek@xxxxxxxxxxxxxxxxxxx
---
Changes in v3:
- Rebase on top of https://patchwork.kernel.org/project/linux-mediatek/patch/20221102100736.37815-1-angelogioacchino.delregno@xxxxxxxxxxxxx/
- Link to v2: https://lore.kernel.org/r/20221125-mtk-mailbox-v2-0-886f70c7173c@xxxxxxxxxxxx

Changes in v2:
- I have managed to repro a different panic. Moving the irq enabling to the very end of probe.
- Link to v1: https://lore.kernel.org/r/20221125-mtk-mailbox-v1-0-2e3ee120850c@xxxxxxxxxxxx
---
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 a460ee26eb11..b18d47ea13a0 100644
--- a/drivers/mailbox/mtk-cmdq-mailbox.c
+++ b/drivers/mailbox/mtk-cmdq-mailbox.c
@@ -569,12 +569,6 @@ static int cmdq_probe(struct platform_device *pdev)
}

cmdq->irq_mask = GENMASK(cmdq->pdata->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);
@@ -641,6 +635,13 @@ static int cmdq_probe(struct platform_device *pdev)

cmdq_init(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;
+ }
+
return 0;
}


---
base-commit: 1642107db81361b4339643eb90af4839e2cf229f
change-id: 20221125-mtk-mailbox-ba6cbd1d91b6

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