From 0f3e5f93fe77bc16e632686b7571d296f91a76be Mon Sep 17 00:00:00 2001 From: Bryan O'Donoghue Date: Wed, 30 Aug 2023 16:16:10 +0100 Subject: media: qcom: camss: Fix VFE-17x vfe_disable_output() commit 3143ad282fc08bf995ee73e32a9e40c527bf265d upstream. There are two problems with the current vfe_disable_output() routine. Firstly we rightly use a spinlock to protect output->gen2.active_num everywhere except for in the IDLE timeout path of vfe_disable_output(). Even if that is not racy "in practice" somehow it is by happenstance not by design. Secondly we do not get consistent behaviour from this routine. On sc8280xp 50% of the time I get "VFE idle timeout - resetting". In this case the subsequent capture will succeed. The other 50% of the time, we don't hit the idle timeout, never do the VFE reset and subsequent captures stall indefinitely. Rewrite the vfe_disable_output() routine to - Quiesce write masters with vfe_wm_stop() - Set active_num = 0 remembering to hold the spinlock when we do so followed by - Reset the VFE Testing on sc8280xp and sdm845 shows this to be a valid fix. Fixes: 7319cdf189bb ("media: camss: Add support for VFE hardware version Titan 170") Cc: stable@vger.kernel.org Signed-off-by: Bryan O'Donoghue Signed-off-by: Hans Verkuil Signed-off-by: Greg Kroah-Hartman --- drivers/media/platform/qcom/camss/camss-vfe-170.c | 22 +++------------------- 1 file changed, 3 insertions(+), 19 deletions(-) diff --git a/drivers/media/platform/qcom/camss/camss-vfe-170.c b/drivers/media/platform/qcom/camss/camss-vfe-170.c index 600150cfc4f7..07b64d257512 100644 --- a/drivers/media/platform/qcom/camss/camss-vfe-170.c +++ b/drivers/media/platform/qcom/camss/camss-vfe-170.c @@ -7,7 +7,6 @@ * Copyright (C) 2020-2021 Linaro Ltd. */ -#include #include #include #include @@ -494,35 +493,20 @@ static int vfe_enable_output(struct vfe_line *line) return 0; } -static int vfe_disable_output(struct vfe_line *line) +static void vfe_disable_output(struct vfe_line *line) { struct vfe_device *vfe = to_vfe(line); struct vfe_output *output = &line->output; unsigned long flags; unsigned int i; - bool done; - int timeout = 0; - - do { - spin_lock_irqsave(&vfe->output_lock, flags); - done = !output->gen2.active_num; - spin_unlock_irqrestore(&vfe->output_lock, flags); - usleep_range(10000, 20000); - - if (timeout++ == 100) { - dev_err(vfe->camss->dev, "VFE idle timeout - resetting\n"); - vfe_reset(vfe); - output->gen2.active_num = 0; - return 0; - } - } while (!done); spin_lock_irqsave(&vfe->output_lock, flags); for (i = 0; i < output->wm_num; i++) vfe_wm_stop(vfe, output->wm_idx[i]); + output->gen2.active_num = 0; spin_unlock_irqrestore(&vfe->output_lock, flags); - return 0; + vfe_reset(vfe); } /* -- cgit v1.2.3