Unverified Commit 57fb32e6 authored by Maxime Ripard's avatar Maxime Ripard
Browse files

drm/vc4: hdmi: Block odd horizontal timings 



The FIFO between the pixelvalve and the HDMI controller runs at 2 pixels
per clock cycle, and cannot deal with odd timings.

Let's reject any mode with such timings.

Signed-off-by: default avatarMaxime Ripard <maxime@cerno.tech>
Reviewed-by: default avatarDave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201029122522.1917579-2-maxime@cerno.tech
parent 63495f6b

drivers/gpu/drm/vc4/vc4_hdmi.c

+12 −0
Original line number Diff line number Diff line
@@ -768,6 +768,11 @@ static int vc4_hdmi_encoder_atomic_check(struct drm_encoder *encoder, 
	struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);

	unsigned long long pixel_rate = mode->clock * 1000;



	if (vc4_hdmi->variant->unsupported_odd_h_timings &&

	    ((mode->hdisplay % 2) || (mode->hsync_start % 2) ||

	     (mode->hsync_end % 2) || (mode->htotal % 2)))

		return -EINVAL;



	if (pixel_rate > vc4_hdmi->variant->max_pixel_clock)

		return -EINVAL;
@@ -780,6 +785,11 @@ vc4_hdmi_encoder_mode_valid(struct drm_encoder *encoder, 
{

	struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);



	if (vc4_hdmi->variant->unsupported_odd_h_timings &&

	    ((mode->hdisplay % 2) || (mode->hsync_start % 2) ||

	     (mode->hsync_end % 2) || (mode->htotal % 2)))

		return MODE_H_ILLEGAL;



	if ((mode->clock * 1000) > vc4_hdmi->variant->max_pixel_clock)

		return MODE_CLOCK_HIGH;
@@ -1832,6 +1842,7 @@ static const struct vc4_hdmi_variant bcm2711_hdmi0_variant = { 
		PHY_LANE_2,

		PHY_LANE_CK,

	},

	.unsupported_odd_h_timings	= true,



	.init_resources		= vc5_hdmi_init_resources,

	.csc_setup		= vc5_hdmi_csc_setup,
@@ -1857,6 +1868,7 @@ static const struct vc4_hdmi_variant bcm2711_hdmi1_variant = { 
		PHY_LANE_CK,

		PHY_LANE_2,

	},

	.unsupported_odd_h_timings	= true,



	.init_resources		= vc5_hdmi_init_resources,

	.csc_setup		= vc5_hdmi_csc_setup,

drivers/gpu/drm/vc4/vc4_hdmi.h

+3 −0
Original line number Diff line number Diff line
@@ -62,6 +62,9 @@ struct vc4_hdmi_variant { 
	 */

	enum vc4_hdmi_phy_channel phy_lane_mapping[4];



	/* The BCM2711 cannot deal with odd horizontal pixel timings */

	bool unsupported_odd_h_timings;



	/* Callback to get the resources (memory region, interrupts,

	 * clocks, etc) for that variant.

	 */