Re: [PATCH 2/2] drm/rockchip: analogix_dp: Refuse to enable PSR if panel doesn't support it

From: Archit Taneja
Date: Mon Oct 03 2016 - 07:14:00 EST

On 09/27/2016 06:58 PM, Sean Paul wrote:
On Fri, Sep 23, 2016 at 10:06 AM, Tomeu Vizoso
<tomeu.vizoso@xxxxxxxxxxxxx> wrote:
There's no point in enabling PSR when the panel doesn't support it.

This also avoids a problem when PSR gets enabled when a CRTC is being
disabled, because sometimes in that situation the DSP_HOLD_VALID_INTR
interrupt on which we wait will never arrive. This was observed on
RK3288 with a panel without PSR (veyron-jaq Chromebook).

It's very easy to reproduce by running the kms_rmfb test in IGT a few

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@xxxxxxxxxxxxx>

Thanks for digging into this.

Reviewed-by: Sean Paul <seanpaul@xxxxxxxxxxxx>

queued to drm-misc.


Cc: Sean Paul <seanpaul@xxxxxxxxxxxx>
Cc: Yakir Yang <ykk@xxxxxxxxxxxxxx>
Cc: Archit Taneja <architt@xxxxxxxxxxxxxx>
drivers/gpu/drm/rockchip/analogix_dp-rockchip.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c b/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
index e83be157cc2a..8548e8271639 100644
--- a/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
+++ b/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
@@ -85,6 +85,9 @@ static void analogix_dp_psr_set(struct drm_encoder *encoder, bool enabled)
struct rockchip_dp_device *dp = to_dp(encoder);
unsigned long flags;

+ if (!analogix_dp_psr_supported(dp->dev))
+ return;
dev_dbg(dp->dev, "%s PSR...\n", enabled ? "Entry" : "Exit");

spin_lock_irqsave(&dp->psr_lock, flags);

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