From: Maxime Ripard <maxime@cerno.tech>
To: Miaoqian Lin <linmq006@gmail.com>
Cc: Emma Anholt <emma@anholt.net>, David Airlie <airlied@linux.ie>,
Daniel Vetter <daniel@ffwll.ch>, Eric Anholt <eric@anholt.net>,
dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] drm/vc4: Fix pm_runtime_get_sync() usage
Date: Wed, 20 Apr 2022 09:51:08 +0200 [thread overview]
Message-ID: <20220420075108.xm5ujthootlpayy2@houat> (raw)
In-Reply-To: <20220420004949.20508-1-linmq006@gmail.com>
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On Wed, Apr 20, 2022 at 12:49:48AM +0000, Miaoqian Lin wrote:
> If the device is already in a runtime PM enabled state
> pm_runtime_get_sync() will return 1, so a test for negative
> value should be used to check for errors.
>
> Also, we need to call pm_runtime_put_noidle() when pm_runtime_get_sync()
> fails, so use pm_runtime_resume_and_get() instead. this function
> will handle this.
>
> Fixes: 4078f5757144 ("drm/vc4: Add DSI driver")
> Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
> ---
> change in v2:
> - switch to pm_runtime_resume_and_get() to fix refcount leak.
> ---
> drivers/gpu/drm/vc4/vc4_dsi.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c
> index 752f921735c6..9d7ffaf6bc70 100644
> --- a/drivers/gpu/drm/vc4/vc4_dsi.c
> +++ b/drivers/gpu/drm/vc4/vc4_dsi.c
> @@ -846,8 +846,8 @@ static void vc4_dsi_encoder_enable(struct drm_encoder *encoder)
> unsigned long phy_clock;
> int ret;
>
> - ret = pm_runtime_get_sync(dev);
> - if (ret) {
> + ret = pm_runtime_resume_and_get(dev);
> + if (ret < 0) {
pm_runtime_resume_and_get will return 0 on success, so the previous check was correct
Maxime
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next prev parent reply other threads:[~2022-04-20 7:52 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-12 7:04 [PATCH] drm/vc4: Fix pm_runtime_get_sync() error checking Miaoqian Lin
2022-04-19 12:44 ` Maxime Ripard
2022-04-20 0:49 ` [PATCH v2] drm/vc4: Fix pm_runtime_get_sync() usage Miaoqian Lin
2022-04-20 7:51 ` Maxime Ripard [this message]
2022-04-20 8:05 ` Miaoqian Lin
2022-04-20 13:28 ` Maxime Ripard
2022-04-20 13:50 ` [PATCH v3] drm/vc4: Use pm_runtime_resume_and_get to fix " Miaoqian Lin
2022-04-21 7:17 ` (subset) " Maxime Ripard
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