| Message ID | 20200925130744.575725-1-maxime@cerno.tech (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/2] drm/vc4: hdmi: Disable Wifi Frequencies | expand |
On Mon, Sep 28, 2020 at 9:06 AM Maxime Ripard <maxime@cerno.tech> wrote: > > There's cross-talk on the RPi4 between the 2.4GHz channels used by the WiFi > chip and some resolutions, most notably 1440p at 60Hz. > > In such a case, we can either reject entirely the mode, or lower slightly > the pixel frequency to remove the overlap. Let's go for the latter. > > Signed-off-by: Maxime Ripard <maxime@cerno.tech> > --- > .../bindings/display/brcm,bcm2711-hdmi.yaml | 6 ++++++ > drivers/gpu/drm/vc4/vc4_hdmi.c | 14 +++++++++++++- > drivers/gpu/drm/vc4/vc4_hdmi.h | 8 ++++++++ > 3 files changed, 27 insertions(+), 1 deletion(-) > > diff --git a/Documentation/devicetree/bindings/display/brcm,bcm2711-hdmi.yaml b/Documentation/devicetree/bindings/display/brcm,bcm2711-hdmi.yaml > index 03a76729d26c..63e7fe999c0a 100644 > --- a/Documentation/devicetree/bindings/display/brcm,bcm2711-hdmi.yaml > +++ b/Documentation/devicetree/bindings/display/brcm,bcm2711-hdmi.yaml > @@ -76,6 +76,12 @@ properties: > resets: > maxItems: 1 > > + raspberrypi,disable-wifi-frequencies: > + type: boolean > + description: > > + Should the pixel frequencies in the WiFi frequencies range be > + avoided? > + > required: > - compatible > - reg > diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c > index acfb4e235214..74da7c00ecd0 100644 > --- a/drivers/gpu/drm/vc4/vc4_hdmi.c > +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c > @@ -877,13 +877,22 @@ static int vc4_hdmi_encoder_atomic_check(struct drm_encoder *encoder, > struct vc4_hdmi_connector_state *vc4_state = conn_state_to_vc4_hdmi_conn_state(conn_state); > struct drm_display_mode *mode = &crtc_state->adjusted_mode; > struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder); > - unsigned long long pixel_rate = mode->clock * 1000; > + unsigned long long pixel_rate; > > if (vc4_hdmi->variant->broken_odd_h_timings && > ((mode->hdisplay % 2) || (mode->hsync_start % 2) || > (mode->hsync_end % 2) || (mode->htotal % 2))) > return -EINVAL; > > + /* > + * The 1440p@60 pixel rate is in the same range than the WiFi > + * channels. Slightly lower the frequency to bring it out of the > + * WiFi range. > + */ > + if (vc4_hdmi->disable_wifi_frequencies && mode->clock == 241500) > + mode->clock = 238560; Don't you want to map for a (narrow) range of frequencies here? Just for that infamous 60p vs 59.99p thing and similar. And I think that would still be in that band you want to avoid. -Daniel > + > + pixel_rate = mode->clock * 1000; > if (mode->flags & DRM_MODE_FLAG_DBLCLK) > pixel_rate *= 2; > > @@ -1837,6 +1846,9 @@ static int vc4_hdmi_bind(struct device *dev, struct device *master, void *data) > vc4_hdmi->hpd_active_low = hpd_gpio_flags & OF_GPIO_ACTIVE_LOW; > } > > + vc4_hdmi->disable_wifi_frequencies = > + of_property_read_bool(dev->of_node, "raspberrypi,disable-wifi-frequencies"); > + > pm_runtime_enable(dev); > > drm_simple_encoder_init(drm, encoder, DRM_MODE_ENCODER_TMDS); > diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.h b/drivers/gpu/drm/vc4/vc4_hdmi.h > index 40e51ece8efe..6618ee758890 100644 > --- a/drivers/gpu/drm/vc4/vc4_hdmi.h > +++ b/drivers/gpu/drm/vc4/vc4_hdmi.h > @@ -143,6 +143,14 @@ struct vc4_hdmi { > int hpd_gpio; > bool hpd_active_low; > > + /* > + * On some systems (like the RPi4), some modes are in the same > + * frequency range than the WiFi channels (1440p@60Hz for > + * example). Should we take evasive actions because that system > + * has a wifi adapter. > + */ > + bool disable_wifi_frequencies; > + > struct cec_adapter *cec_adap; > struct cec_msg cec_rx_msg; > bool cec_tx_ok; > -- > 2.26.2 > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel
On Fri, Sep 25, 2020 at 03:07:43PM +0200, Maxime Ripard wrote: > There's cross-talk on the RPi4 between the 2.4GHz channels used by the WiFi > chip and some resolutions, most notably 1440p at 60Hz. > > In such a case, we can either reject entirely the mode, or lower slightly > the pixel frequency to remove the overlap. Let's go for the latter. > > Signed-off-by: Maxime Ripard <maxime@cerno.tech> > --- > .../bindings/display/brcm,bcm2711-hdmi.yaml | 6 ++++++ > drivers/gpu/drm/vc4/vc4_hdmi.c | 14 +++++++++++++- > drivers/gpu/drm/vc4/vc4_hdmi.h | 8 ++++++++ > 3 files changed, 27 insertions(+), 1 deletion(-) > > diff --git a/Documentation/devicetree/bindings/display/brcm,bcm2711-hdmi.yaml b/Documentation/devicetree/bindings/display/brcm,bcm2711-hdmi.yaml > index 03a76729d26c..63e7fe999c0a 100644 > --- a/Documentation/devicetree/bindings/display/brcm,bcm2711-hdmi.yaml > +++ b/Documentation/devicetree/bindings/display/brcm,bcm2711-hdmi.yaml > @@ -76,6 +76,12 @@ properties: > resets: > maxItems: 1 > > + raspberrypi,disable-wifi-frequencies: > + type: boolean > + description: > > + Should the pixel frequencies in the WiFi frequencies range be > + avoided? Based on googling the issue, perhaps should be a common property?
Hi Daniel, On Mon, Sep 28, 2020 at 11:02:11AM +0200, Daniel Vetter wrote: > On Mon, Sep 28, 2020 at 9:06 AM Maxime Ripard <maxime@cerno.tech> wrote: > > > > There's cross-talk on the RPi4 between the 2.4GHz channels used by the WiFi > > chip and some resolutions, most notably 1440p at 60Hz. > > > > In such a case, we can either reject entirely the mode, or lower slightly > > the pixel frequency to remove the overlap. Let's go for the latter. > > > > Signed-off-by: Maxime Ripard <maxime@cerno.tech> > > --- > > .../bindings/display/brcm,bcm2711-hdmi.yaml | 6 ++++++ > > drivers/gpu/drm/vc4/vc4_hdmi.c | 14 +++++++++++++- > > drivers/gpu/drm/vc4/vc4_hdmi.h | 8 ++++++++ > > 3 files changed, 27 insertions(+), 1 deletion(-) > > > > diff --git a/Documentation/devicetree/bindings/display/brcm,bcm2711-hdmi.yaml b/Documentation/devicetree/bindings/display/brcm,bcm2711-hdmi.yaml > > index 03a76729d26c..63e7fe999c0a 100644 > > --- a/Documentation/devicetree/bindings/display/brcm,bcm2711-hdmi.yaml > > +++ b/Documentation/devicetree/bindings/display/brcm,bcm2711-hdmi.yaml > > @@ -76,6 +76,12 @@ properties: > > resets: > > maxItems: 1 > > > > + raspberrypi,disable-wifi-frequencies: > > + type: boolean > > + description: > > > + Should the pixel frequencies in the WiFi frequencies range be > > + avoided? > > + > > required: > > - compatible > > - reg > > diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c > > index acfb4e235214..74da7c00ecd0 100644 > > --- a/drivers/gpu/drm/vc4/vc4_hdmi.c > > +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c > > @@ -877,13 +877,22 @@ static int vc4_hdmi_encoder_atomic_check(struct drm_encoder *encoder, > > struct vc4_hdmi_connector_state *vc4_state = conn_state_to_vc4_hdmi_conn_state(conn_state); > > struct drm_display_mode *mode = &crtc_state->adjusted_mode; > > struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder); > > - unsigned long long pixel_rate = mode->clock * 1000; > > + unsigned long long pixel_rate; > > > > if (vc4_hdmi->variant->broken_odd_h_timings && > > ((mode->hdisplay % 2) || (mode->hsync_start % 2) || > > (mode->hsync_end % 2) || (mode->htotal % 2))) > > return -EINVAL; > > > > + /* > > + * The 1440p@60 pixel rate is in the same range than the WiFi > > + * channels. Slightly lower the frequency to bring it out of the > > + * WiFi range. > > + */ > > + if (vc4_hdmi->disable_wifi_frequencies && mode->clock == 241500) > > + mode->clock = 238560; > > Don't you want to map for a (narrow) range of frequencies here? Just > for that infamous 60p vs 59.99p thing and similar. And I think that > would still be in that band you want to avoid. Testing for a range seems better indeed, I'll send a new version Thanks! Maxime
Hi Rob, On Tue, Sep 29, 2020 at 02:00:55PM -0500, Rob Herring wrote: > On Fri, Sep 25, 2020 at 03:07:43PM +0200, Maxime Ripard wrote: > > There's cross-talk on the RPi4 between the 2.4GHz channels used by the WiFi > > chip and some resolutions, most notably 1440p at 60Hz. > > > > In such a case, we can either reject entirely the mode, or lower slightly > > the pixel frequency to remove the overlap. Let's go for the latter. > > > > Signed-off-by: Maxime Ripard <maxime@cerno.tech> > > --- > > .../bindings/display/brcm,bcm2711-hdmi.yaml | 6 ++++++ > > drivers/gpu/drm/vc4/vc4_hdmi.c | 14 +++++++++++++- > > drivers/gpu/drm/vc4/vc4_hdmi.h | 8 ++++++++ > > 3 files changed, 27 insertions(+), 1 deletion(-) > > > > diff --git a/Documentation/devicetree/bindings/display/brcm,bcm2711-hdmi.yaml b/Documentation/devicetree/bindings/display/brcm,bcm2711-hdmi.yaml > > index 03a76729d26c..63e7fe999c0a 100644 > > --- a/Documentation/devicetree/bindings/display/brcm,bcm2711-hdmi.yaml > > +++ b/Documentation/devicetree/bindings/display/brcm,bcm2711-hdmi.yaml > > @@ -76,6 +76,12 @@ properties: > > resets: > > maxItems: 1 > > > > + raspberrypi,disable-wifi-frequencies: > > + type: boolean > > + description: > > > + Should the pixel frequencies in the WiFi frequencies range be > > + avoided? > > Based on googling the issue, perhaps should be a common property? This is a fairly generic issue indeed, but went for the most non-intrusive way. Do you have a better idea of a generic name, or do you just want me to drop the vendor prefix? Maxime
diff --git a/Documentation/devicetree/bindings/display/brcm,bcm2711-hdmi.yaml b/Documentation/devicetree/bindings/display/brcm,bcm2711-hdmi.yaml index 03a76729d26c..63e7fe999c0a 100644 --- a/Documentation/devicetree/bindings/display/brcm,bcm2711-hdmi.yaml +++ b/Documentation/devicetree/bindings/display/brcm,bcm2711-hdmi.yaml @@ -76,6 +76,12 @@ properties: resets: maxItems: 1 + raspberrypi,disable-wifi-frequencies: + type: boolean + description: > + Should the pixel frequencies in the WiFi frequencies range be + avoided? + required: - compatible - reg diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c index acfb4e235214..74da7c00ecd0 100644 --- a/drivers/gpu/drm/vc4/vc4_hdmi.c +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c @@ -877,13 +877,22 @@ static int vc4_hdmi_encoder_atomic_check(struct drm_encoder *encoder, struct vc4_hdmi_connector_state *vc4_state = conn_state_to_vc4_hdmi_conn_state(conn_state); struct drm_display_mode *mode = &crtc_state->adjusted_mode; struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder); - unsigned long long pixel_rate = mode->clock * 1000; + unsigned long long pixel_rate; if (vc4_hdmi->variant->broken_odd_h_timings && ((mode->hdisplay % 2) || (mode->hsync_start % 2) || (mode->hsync_end % 2) || (mode->htotal % 2))) return -EINVAL; + /* + * The 1440p@60 pixel rate is in the same range than the WiFi + * channels. Slightly lower the frequency to bring it out of the + * WiFi range. + */ + if (vc4_hdmi->disable_wifi_frequencies && mode->clock == 241500) + mode->clock = 238560; + + pixel_rate = mode->clock * 1000; if (mode->flags & DRM_MODE_FLAG_DBLCLK) pixel_rate *= 2; @@ -1837,6 +1846,9 @@ static int vc4_hdmi_bind(struct device *dev, struct device *master, void *data) vc4_hdmi->hpd_active_low = hpd_gpio_flags & OF_GPIO_ACTIVE_LOW; } + vc4_hdmi->disable_wifi_frequencies = + of_property_read_bool(dev->of_node, "raspberrypi,disable-wifi-frequencies"); + pm_runtime_enable(dev); drm_simple_encoder_init(drm, encoder, DRM_MODE_ENCODER_TMDS); diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.h b/drivers/gpu/drm/vc4/vc4_hdmi.h index 40e51ece8efe..6618ee758890 100644 --- a/drivers/gpu/drm/vc4/vc4_hdmi.h +++ b/drivers/gpu/drm/vc4/vc4_hdmi.h @@ -143,6 +143,14 @@ struct vc4_hdmi { int hpd_gpio; bool hpd_active_low; + /* + * On some systems (like the RPi4), some modes are in the same + * frequency range than the WiFi channels (1440p@60Hz for + * example). Should we take evasive actions because that system + * has a wifi adapter. + */ + bool disable_wifi_frequencies; + struct cec_adapter *cec_adap; struct cec_msg cec_rx_msg; bool cec_tx_ok;
There's cross-talk on the RPi4 between the 2.4GHz channels used by the WiFi chip and some resolutions, most notably 1440p at 60Hz. In such a case, we can either reject entirely the mode, or lower slightly the pixel frequency to remove the overlap. Let's go for the latter. Signed-off-by: Maxime Ripard <maxime@cerno.tech> --- .../bindings/display/brcm,bcm2711-hdmi.yaml | 6 ++++++ drivers/gpu/drm/vc4/vc4_hdmi.c | 14 +++++++++++++- drivers/gpu/drm/vc4/vc4_hdmi.h | 8 ++++++++ 3 files changed, 27 insertions(+), 1 deletion(-)