Re: [PATCH v8 02/10] drm/vc4: hdmi: Fix HPD GPIO detection

[Dave Stevenson]

On Mon, 25 Oct 2021 at 16:29, Maxime Ripard  wrote:
>
> Prior to commit 6800234ceee0 ("drm/vc4: hdmi: Convert to gpiod"), in the
> detect hook, if we had an HPD GPIO we would only rely on it and return
> whatever state it was in.
>
> However, that commit changed that by mistake to only consider the case
> where we have a GPIO and it returns a logical high, and would fall back
> to the other methods otherwise.
>
> Since we can read the EDIDs when the HPD signal is low on some displays,
> we changed the detection status from disconnected to connected, and we
> would ignore an HPD pulse.
>
> Fixes: 6800234ceee0 ("drm/vc4: hdmi: Convert to gpiod")
> Signed-off-by: Maxime Ripard 

Reviewed-by: Dave Stevenson 

> ---
>  drivers/gpu/drm/vc4/vc4_hdmi.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
> index 338968275724..dde67b991ae7 100644
> --- a/drivers/gpu/drm/vc4/vc4_hdmi.c
> +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
> @@ -190,9 +190,9 @@ vc4_hdmi_connector_detect(struct drm_connector 
> *connector, bool force)
>
> WARN_ON(pm_runtime_resume_and_get(_hdmi->pdev->dev));
>
> -   if (vc4_hdmi->hpd_gpio &&
> -   gpiod_get_value_cansleep(vc4_hdmi->hpd_gpio)) {
> -   connected = true;
> +   if (vc4_hdmi->hpd_gpio) {
> +   if (gpiod_get_value_cansleep(vc4_hdmi->hpd_gpio))
> +   connected = true;
> } else {
> unsigned long flags;
> u32 hotplug;
> --
> 2.31.1
>

[PATCH v8 02/10] drm/vc4: hdmi: Fix HPD GPIO detection

[Maxime Ripard]

Prior to commit 6800234ceee0 ("drm/vc4: hdmi: Convert to gpiod"), in the
detect hook, if we had an HPD GPIO we would only rely on it and return
whatever state it was in.

However, that commit changed that by mistake to only consider the case
where we have a GPIO and it returns a logical high, and would fall back
to the other methods otherwise.

Since we can read the EDIDs when the HPD signal is low on some displays,
we changed the detection status from disconnected to connected, and we
would ignore an HPD pulse.

Fixes: 6800234ceee0 ("drm/vc4: hdmi: Convert to gpiod")
Signed-off-by: Maxime Ripard 
---
 drivers/gpu/drm/vc4/vc4_hdmi.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index 338968275724..dde67b991ae7 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -190,9 +190,9 @@ vc4_hdmi_connector_detect(struct drm_connector *connector, 
bool force)
 
WARN_ON(pm_runtime_resume_and_get(_hdmi->pdev->dev));
 
-   if (vc4_hdmi->hpd_gpio &&
-   gpiod_get_value_cansleep(vc4_hdmi->hpd_gpio)) {
-   connected = true;
+   if (vc4_hdmi->hpd_gpio) {
+   if (gpiod_get_value_cansleep(vc4_hdmi->hpd_gpio))
+   connected = true;
} else {
unsigned long flags;
u32 hotplug;
-- 
2.31.1