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Commit 1a1841d3 authored by Ben Skeggs's avatar Ben Skeggs
Browse files

drm/nouveau: do not forcibly power on lvds panels 



This fix was put in place to fix a bug where the eDP panel on certain
laptops fails to respond over the aux channel after suspend.

It appears that on some systems (Dell M6600, with LVDS panel) there's a
very bad interaction with the eDP init table that causes the SOR to get
very confused and not drive the panel correctly, leading to bleed.

A DPMS off/on cycle is enough to bring it back, but, this will avoid the
problem by not touching the panel GPIOs at times we're not meant to.

Signed-off-by: default avatarBen Skeggs <bskeggs@redhat.com>
parent 4459146d

drivers/gpu/drm/nouveau/nouveau_connector.c

+26 −4
Original line number Diff line number Diff line
@@ -127,12 +127,26 @@ nouveau_connector_ddc_detect(struct drm_connector *connector, 
			     struct nouveau_encoder **pnv_encoder)

{

	struct drm_device *dev = connector->dev;

	struct nouveau_connector *nv_connector = nouveau_connector(connector);

	struct nouveau_drm *drm = nouveau_drm(dev);

	struct nouveau_gpio *gpio = nouveau_gpio(drm->device);

	struct nouveau_i2c *i2c = nouveau_i2c(drm->device);

	int i;

	struct nouveau_i2c_port *port = NULL;

	int i, panel = -ENODEV;



	/* eDP panels need powering on by us (if the VBIOS doesn't default it

	 * to on) before doing any AUX channel transactions.  LVDS panel power

	 * is handled by the SOR itself, and not required for LVDS DDC.

	 */

	if (nv_connector->type == DCB_CONNECTOR_eDP) {

		panel = gpio->get(gpio, 0, DCB_GPIO_PANEL_POWER, 0xff);

		if (panel == 0) {

			gpio->set(gpio, 0, DCB_GPIO_PANEL_POWER, 0xff, 1);

			msleep(300);

		}

	}



	for (i = 0; i < DRM_CONNECTOR_MAX_ENCODER; i++) {

		struct nouveau_i2c_port *port = NULL;

		struct nouveau_encoder *nv_encoder;

		struct drm_mode_object *obj;

		int id;
@@ -150,11 +164,19 @@ nouveau_connector_ddc_detect(struct drm_connector *connector, 
			port = i2c->find(i2c, nv_encoder->dcb->i2c_index);

		if (port && nv_probe_i2c(port, 0x50)) {

			*pnv_encoder = nv_encoder;

			return port;

			break;

		}



		port = NULL;

	}



	return NULL;

	/* eDP panel not detected, restore panel power GPIO to previous

	 * state to avoid confusing the SOR for other output types.

	 */

	if (!port && panel == 0)

		gpio->set(gpio, 0, DCB_GPIO_PANEL_POWER, 0xff, panel);



	return port;

}



static struct nouveau_encoder *

drivers/gpu/drm/nouveau/nouveau_display.c

+0 −9
Original line number Diff line number Diff line
@@ -225,15 +225,6 @@ nouveau_display_init(struct drm_device *dev) 
	if (ret)

		return ret;



	/* power on internal panel if it's not already.  the init tables of

	 * some vbios default this to off for some reason, causing the

	 * panel to not work after resume

	 */

	if (gpio && gpio->get(gpio, 0, DCB_GPIO_PANEL_POWER, 0xff) == 0) {

		gpio->set(gpio, 0, DCB_GPIO_PANEL_POWER, 0xff, 1);

		msleep(300);

	}



	/* enable polling for external displays */

	drm_kms_helper_poll_enable(dev);