[PATCHv4] drm/sun4i: validate modes for HDMI

Submitted by Hans Verkuil on Dec. 15, 2017, 4:46 p.m.

Details

Message ID 0fa230a8-d01d-561a-f74f-6b4fd421255b@xs4all.nl
State New
Headers show
Series "drm/sun4i: validate modes for HDMI" ( rev: 4 ) in DRI devel

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Commit Message

Hans Verkuil Dec. 15, 2017, 4:46 p.m.
When I connected my cubieboard running 4.15-rc1 to my 4k display I got no picture. Some
digging found that there is no check against the upper pixelclock limit of the HDMI
output, so X selects a 4kp60 format at 594 MHz, which obviously won't work.

The patch below adds a check for the upper bound of what this hardware can do, and
it checks if the requested tmds clock can be obtained.

It also allows for the ± 0.5% pixel clock variation that the HDMI spec permits.

That code is based on commit 22d0be2a557e53a22feb484e8fce255fe09e6ad5 from
Jose Abreu for drm/arc.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
Changes since v3:
- Move the mode_valid callback to struct drm_encoder_helper_funcs.
  I'm assuming this is the correct struct, since this check is specific to the
  hdmi encoder.
Changes since v2:
- Allow for the 0.5% variation.
---
 drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

Patch hide | download patch | download mbox

diff --git a/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c b/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
index dda904ec0534..500b6fb3e028 100644
--- a/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
+++ b/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
@@ -175,11 +175,31 @@  static void sun4i_hdmi_mode_set(struct drm_encoder *encoder,
 	writel(val, hdmi->base + SUN4I_HDMI_VID_TIMING_POL_REG);
 }

+static enum drm_mode_status sun4i_hdmi_mode_valid(struct drm_encoder *encoder,
+					const struct drm_display_mode *mode)
+{
+	struct sun4i_hdmi *hdmi = drm_encoder_to_sun4i_hdmi(encoder);
+	unsigned long rate = mode->clock * 1000;
+	unsigned long diff = rate / 200; /* +-0.5% allowed by HDMI spec */
+	long rounded_rate;
+
+	/* 165 MHz is the typical max pixelclock frequency for HDMI <= 1.2 */
+	if (rate > 165000000)
+		return MODE_CLOCK_HIGH;
+	rounded_rate = clk_round_rate(hdmi->tmds_clk, rate);
+	if (rounded_rate > 0 &&
+	    max_t(unsigned long, rounded_rate, rate) -
+	    min_t(unsigned long, rounded_rate, rate) < diff)
+		return MODE_OK;
+	return MODE_NOCLOCK;
+}
+
 static const struct drm_encoder_helper_funcs sun4i_hdmi_helper_funcs = {
 	.atomic_check	= sun4i_hdmi_atomic_check,
 	.disable	= sun4i_hdmi_disable,
 	.enable		= sun4i_hdmi_enable,
 	.mode_set	= sun4i_hdmi_mode_set,
+	.mode_valid	= sun4i_hdmi_mode_valid,
 };

 static const struct drm_encoder_funcs sun4i_hdmi_funcs = {

Comments

On Fri, Dec 15, 2017 at 05:46:19PM +0100, Hans Verkuil wrote:
> When I connected my cubieboard running 4.15-rc1 to my 4k display I got no picture. Some
> digging found that there is no check against the upper pixelclock limit of the HDMI
> output, so X selects a 4kp60 format at 594 MHz, which obviously won't work.
> 
> The patch below adds a check for the upper bound of what this hardware can do, and
> it checks if the requested tmds clock can be obtained.
> 
> It also allows for the ± 0.5% pixel clock variation that the HDMI spec permits.
> 
> That code is based on commit 22d0be2a557e53a22feb484e8fce255fe09e6ad5 from
> Jose Abreu for drm/arc.
> 
> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
> ---
> Changes since v3:
> - Move the mode_valid callback to struct drm_encoder_helper_funcs.
>   I'm assuming this is the correct struct, since this check is specific to the
>   hdmi encoder.

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

I think sun4i is in drm-misc, so feel free to push.

Cheers, Daniel


> Changes since v2:
> - Allow for the 0.5% variation.
> ---
>  drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
> 
> diff --git a/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c b/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
> index dda904ec0534..500b6fb3e028 100644
> --- a/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
> +++ b/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
> @@ -175,11 +175,31 @@ static void sun4i_hdmi_mode_set(struct drm_encoder *encoder,
>  	writel(val, hdmi->base + SUN4I_HDMI_VID_TIMING_POL_REG);
>  }
> 
> +static enum drm_mode_status sun4i_hdmi_mode_valid(struct drm_encoder *encoder,
> +					const struct drm_display_mode *mode)
> +{
> +	struct sun4i_hdmi *hdmi = drm_encoder_to_sun4i_hdmi(encoder);
> +	unsigned long rate = mode->clock * 1000;
> +	unsigned long diff = rate / 200; /* +-0.5% allowed by HDMI spec */
> +	long rounded_rate;
> +
> +	/* 165 MHz is the typical max pixelclock frequency for HDMI <= 1.2 */
> +	if (rate > 165000000)
> +		return MODE_CLOCK_HIGH;
> +	rounded_rate = clk_round_rate(hdmi->tmds_clk, rate);
> +	if (rounded_rate > 0 &&
> +	    max_t(unsigned long, rounded_rate, rate) -
> +	    min_t(unsigned long, rounded_rate, rate) < diff)
> +		return MODE_OK;
> +	return MODE_NOCLOCK;
> +}
> +
>  static const struct drm_encoder_helper_funcs sun4i_hdmi_helper_funcs = {
>  	.atomic_check	= sun4i_hdmi_atomic_check,
>  	.disable	= sun4i_hdmi_disable,
>  	.enable		= sun4i_hdmi_enable,
>  	.mode_set	= sun4i_hdmi_mode_set,
> +	.mode_valid	= sun4i_hdmi_mode_valid,
>  };
> 
>  static const struct drm_encoder_funcs sun4i_hdmi_funcs = {
> -- 
> 2.15.0
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
Hi,

On Fri, Dec 15, 2017 at 06:06:32PM +0100, Daniel Vetter wrote:
> On Fri, Dec 15, 2017 at 05:46:19PM +0100, Hans Verkuil wrote:
> > When I connected my cubieboard running 4.15-rc1 to my 4k display I got no picture. Some
> > digging found that there is no check against the upper pixelclock limit of the HDMI
> > output, so X selects a 4kp60 format at 594 MHz, which obviously won't work.
> > 
> > The patch below adds a check for the upper bound of what this hardware can do, and
> > it checks if the requested tmds clock can be obtained.
> > 
> > It also allows for the ± 0.5% pixel clock variation that the HDMI spec permits.
> > 
> > That code is based on commit 22d0be2a557e53a22feb484e8fce255fe09e6ad5 from
> > Jose Abreu for drm/arc.
> > 
> > Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
> > ---
> > Changes since v3:
> > - Move the mode_valid callback to struct drm_encoder_helper_funcs.
> >   I'm assuming this is the correct struct, since this check is specific to the
> >   hdmi encoder.
> 
> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> 
> I think sun4i is in drm-misc, so feel free to push.

I already pushed the v3. Hans, can you provide an additional patch? on top of your v3?

Thanks!
Maxime
On Mon, Dec 18, 2017 at 08:50:46AM +0100, Maxime Ripard wrote:
> Hi,
> 
> On Fri, Dec 15, 2017 at 06:06:32PM +0100, Daniel Vetter wrote:
> > On Fri, Dec 15, 2017 at 05:46:19PM +0100, Hans Verkuil wrote:
> > > When I connected my cubieboard running 4.15-rc1 to my 4k display I got no picture. Some
> > > digging found that there is no check against the upper pixelclock limit of the HDMI
> > > output, so X selects a 4kp60 format at 594 MHz, which obviously won't work.
> > > 
> > > The patch below adds a check for the upper bound of what this hardware can do, and
> > > it checks if the requested tmds clock can be obtained.
> > > 
> > > It also allows for the ± 0.5% pixel clock variation that the HDMI spec permits.
> > > 
> > > That code is based on commit 22d0be2a557e53a22feb484e8fce255fe09e6ad5 from
> > > Jose Abreu for drm/arc.
> > > 
> > > Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
> > > ---
> > > Changes since v3:
> > > - Move the mode_valid callback to struct drm_encoder_helper_funcs.
> > >   I'm assuming this is the correct struct, since this check is specific to the
> > >   hdmi encoder.
> > 
> > Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> > 
> > I think sun4i is in drm-misc, so feel free to push.
> 
> I already pushed the v3. Hans, can you provide an additional patch? on top of your v3?

Pretty sure I reviewed before you pushed, why should I bother?

Also, for people with commit rights it's imo better to let them push, to
avoid such hiccups.

Thanks, Daniel
On 19/12/17 11:05, Daniel Vetter wrote:
> On Mon, Dec 18, 2017 at 08:50:46AM +0100, Maxime Ripard wrote:
>> Hi,
>>
>> On Fri, Dec 15, 2017 at 06:06:32PM +0100, Daniel Vetter wrote:
>>> On Fri, Dec 15, 2017 at 05:46:19PM +0100, Hans Verkuil wrote:
>>>> When I connected my cubieboard running 4.15-rc1 to my 4k display I got no picture. Some
>>>> digging found that there is no check against the upper pixelclock limit of the HDMI
>>>> output, so X selects a 4kp60 format at 594 MHz, which obviously won't work.
>>>>
>>>> The patch below adds a check for the upper bound of what this hardware can do, and
>>>> it checks if the requested tmds clock can be obtained.
>>>>
>>>> It also allows for the ± 0.5% pixel clock variation that the HDMI spec permits.
>>>>
>>>> That code is based on commit 22d0be2a557e53a22feb484e8fce255fe09e6ad5 from
>>>> Jose Abreu for drm/arc.
>>>>
>>>> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
>>>> ---
>>>> Changes since v3:
>>>> - Move the mode_valid callback to struct drm_encoder_helper_funcs.
>>>>   I'm assuming this is the correct struct, since this check is specific to the
>>>>   hdmi encoder.
>>>
>>> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
>>>
>>> I think sun4i is in drm-misc, so feel free to push.
>>
>> I already pushed the v3. Hans, can you provide an additional patch? on top of your v3?
> 
> Pretty sure I reviewed before you pushed, why should I bother?
> 
> Also, for people with commit rights it's imo better to let them push, to
> avoid such hiccups.
> 
> Thanks, Daniel
> 

Since I'm on vacation I would also very much appreciate it if you can take care of it,
Maxime. If not, then let me know and I'll try to whip up a v3-v4 patch for you.

Regards,

	Hans
Hi Daniel,

On Tue, Dec 19, 2017 at 11:05:04AM +0100, Daniel Vetter wrote:
> On Mon, Dec 18, 2017 at 08:50:46AM +0100, Maxime Ripard wrote:
> > Hi,
> > 
> > On Fri, Dec 15, 2017 at 06:06:32PM +0100, Daniel Vetter wrote:
> > > On Fri, Dec 15, 2017 at 05:46:19PM +0100, Hans Verkuil wrote:
> > > > When I connected my cubieboard running 4.15-rc1 to my 4k display I got no picture. Some
> > > > digging found that there is no check against the upper pixelclock limit of the HDMI
> > > > output, so X selects a 4kp60 format at 594 MHz, which obviously won't work.
> > > > 
> > > > The patch below adds a check for the upper bound of what this hardware can do, and
> > > > it checks if the requested tmds clock can be obtained.
> > > > 
> > > > It also allows for the ± 0.5% pixel clock variation that the HDMI spec permits.
> > > > 
> > > > That code is based on commit 22d0be2a557e53a22feb484e8fce255fe09e6ad5 from
> > > > Jose Abreu for drm/arc.
> > > > 
> > > > Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
> > > > ---
> > > > Changes since v3:
> > > > - Move the mode_valid callback to struct drm_encoder_helper_funcs.
> > > >   I'm assuming this is the correct struct, since this check is specific to the
> > > >   hdmi encoder.
> > > 
> > > Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> > > 
> > > I think sun4i is in drm-misc, so feel free to push.
> > 
> > I already pushed the v3. Hans, can you provide an additional patch? on top of your v3?
> 
> Pretty sure I reviewed before you pushed, why should I bother?

Yeah, sorry. My mailer didn't fetch your mail until monday morning, so
your review went unnoticed :/

I just pushed a patch to bring the changes to the v4, with your
Acked-by as you told on IRC.

Sorry again,
Maxime