From: Mads Bligaard Nielsen <bli@xxxxxxxxxxxxxxx> Moved IRQ registration down to end of adv7511_probe(). If an IRQ already is pending during adv7511_probe (before adv7511_cec_init) then cec_received_msg_ts could crash using uninitialized data: Unable to handle kernel read from unreadable memory at virtual address 00000000000003d5 Internal error: Oops: 96000004 [#1] PREEMPT_RT SMP Call trace: cec_received_msg_ts+0x48/0x990 [cec] adv7511_cec_irq_process+0x1cc/0x308 [adv7511] adv7511_irq_process+0xd8/0x120 [adv7511] adv7511_irq_handler+0x1c/0x30 [adv7511] irq_thread_fn+0x30/0xa0 irq_thread+0x14c/0x238 kthread+0x190/0x1a8 Fixes: 3b1b975003e4 ("drm: adv7511/33: add HDMI CEC support") Signed-off-by: Mads Bligaard Nielsen <bli@xxxxxxxxxxxxxxx> Signed-off-by: Alvin Šipraga <alsi@xxxxxxxxxxxxxxx> --- Changes in v2: - rebase on latest drm-misc-fixes - no other changes - RESEND - Link to v1: https://lore.kernel.org/r/20231014-adv7511-cec-irq-crash-fix-v1-1-3389486c8373@xxxxxxxxxxxxxxx --- drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c index 8be235144f6d..6fc292393c67 100644 --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c @@ -1277,17 +1277,6 @@ static int adv7511_probe(struct i2c_client *i2c) INIT_WORK(&adv7511->hpd_work, adv7511_hpd_work); - if (i2c->irq) { - init_waitqueue_head(&adv7511->wq); - - ret = devm_request_threaded_irq(dev, i2c->irq, NULL, - adv7511_irq_handler, - IRQF_ONESHOT, dev_name(dev), - adv7511); - if (ret) - goto err_unregister_cec; - } - adv7511_power_off(adv7511); i2c_set_clientdata(i2c, adv7511); @@ -1311,6 +1300,17 @@ static int adv7511_probe(struct i2c_client *i2c) adv7511_audio_init(dev, adv7511); + if (i2c->irq) { + init_waitqueue_head(&adv7511->wq); + + ret = devm_request_threaded_irq(dev, i2c->irq, NULL, + adv7511_irq_handler, + IRQF_ONESHOT, dev_name(dev), + adv7511); + if (ret) + goto err_unregister_audio; + } + if (adv7511->info->has_dsi) { ret = adv7533_attach_dsi(adv7511); if (ret) --- base-commit: 335126937753844d36036984e96a8f343538a778 change-id: 20231014-adv7511-cec-irq-crash-fix-6fdd9093dc7a