From 9a7bc6b0c456bdc642269659fb13f29a8c13815b Mon Sep 17 00:00:00 2001 From: Pawel Osciak Date: Tue, 21 Oct 2014 08:07:01 -0300 Subject: [PATCH] [media] s5p-mfc: Don't crash the kernel if the watchdog kicks in If the software watchdog kicks in, the watchdog worker is not synchronized with hardware interrupts and does not block other instances. It's possible for it to clear the hw_lock, making other instances trigger a BUG() on hw_lock checks. Since it's not fatal to clear the hw_lock to zero twice, just WARN in those cases for now. We should not explode, as firmware will return errors as needed for other instances after it's reloaded, or they will time out. A clean fix should involve killing other instances when watchdog kicks in, but requires a major redesign of locking in the driver. Signed-off-by: Pawel Osciak Signed-off-by: Kiran AVND Signed-off-by: Arun Kumar K Signed-off-by: Kamil Debski Signed-off-by: Mauro Carvalho Chehab --- drivers/media/platform/s5p-mfc/s5p_mfc.c | 21 +++++++-------------- 1 file changed, 7 insertions(+), 14 deletions(-) diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc.c b/drivers/media/platform/s5p-mfc/s5p_mfc.c index eb710554cb2d..8620236200b7 100644 --- a/drivers/media/platform/s5p-mfc/s5p_mfc.c +++ b/drivers/media/platform/s5p-mfc/s5p_mfc.c @@ -342,8 +342,7 @@ static void s5p_mfc_handle_frame(struct s5p_mfc_ctx *ctx, ctx->state = MFCINST_RES_CHANGE_INIT; s5p_mfc_hw_call_void(dev->mfc_ops, clear_int_flags, dev); wake_up_ctx(ctx, reason, err); - if (test_and_clear_bit(0, &dev->hw_lock) == 0) - BUG(); + WARN_ON(test_and_clear_bit(0, &dev->hw_lock) == 0); s5p_mfc_clock_off(); s5p_mfc_hw_call_void(dev->mfc_ops, try_run, dev); return; @@ -415,8 +414,7 @@ leave_handle_frame: clear_work_bit(ctx); s5p_mfc_hw_call_void(dev->mfc_ops, clear_int_flags, dev); wake_up_ctx(ctx, reason, err); - if (test_and_clear_bit(0, &dev->hw_lock) == 0) - BUG(); + WARN_ON(test_and_clear_bit(0, &dev->hw_lock) == 0); s5p_mfc_clock_off(); /* if suspending, wake up device and do not try_run again*/ if (test_bit(0, &dev->enter_suspend)) @@ -463,8 +461,7 @@ static void s5p_mfc_handle_error(struct s5p_mfc_dev *dev, break; } } - if (test_and_clear_bit(0, &dev->hw_lock) == 0) - BUG(); + WARN_ON(test_and_clear_bit(0, &dev->hw_lock) == 0); s5p_mfc_hw_call_void(dev->mfc_ops, clear_int_flags, dev); s5p_mfc_clock_off(); wake_up_dev(dev, reason, err); @@ -518,8 +515,7 @@ static void s5p_mfc_handle_seq_done(struct s5p_mfc_ctx *ctx, } s5p_mfc_hw_call_void(dev->mfc_ops, clear_int_flags, dev); clear_work_bit(ctx); - if (test_and_clear_bit(0, &dev->hw_lock) == 0) - BUG(); + WARN_ON(test_and_clear_bit(0, &dev->hw_lock) == 0); s5p_mfc_clock_off(); s5p_mfc_hw_call_void(dev->mfc_ops, try_run, dev); wake_up_ctx(ctx, reason, err); @@ -557,16 +553,14 @@ static void s5p_mfc_handle_init_buffers(struct s5p_mfc_ctx *ctx, } else { ctx->dpb_flush_flag = 0; } - if (test_and_clear_bit(0, &dev->hw_lock) == 0) - BUG(); + WARN_ON(test_and_clear_bit(0, &dev->hw_lock) == 0); s5p_mfc_clock_off(); wake_up(&ctx->queue); s5p_mfc_hw_call_void(dev->mfc_ops, try_run, dev); } else { - if (test_and_clear_bit(0, &dev->hw_lock) == 0) - BUG(); + WARN_ON(test_and_clear_bit(0, &dev->hw_lock) == 0); s5p_mfc_clock_off(); @@ -643,8 +637,7 @@ static irqreturn_t s5p_mfc_irq(int irq, void *priv) mfc_err("post_frame_start() failed\n"); s5p_mfc_hw_call_void(dev->mfc_ops, clear_int_flags, dev); wake_up_ctx(ctx, reason, err); - if (test_and_clear_bit(0, &dev->hw_lock) == 0) - BUG(); + WARN_ON(test_and_clear_bit(0, &dev->hw_lock) == 0); s5p_mfc_clock_off(); s5p_mfc_hw_call_void(dev->mfc_ops, try_run, dev); } else { -- 2.30.2