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Commit c0beefd2 authored by Gaurav K Singh's avatar Gaurav K Singh Committed by Daniel Vetter
Browse files

drm/i915: Software workaround for getting the HW status of DSI Port C on BYT 



Due to hardware limitations on BYT, MIPI Port C DPI Enable bit
does not get set. To check whether DSI Port C was enabled in BIOS,
check the Pipe B enable bit for DSI Port C. In hardware, DSI Port C
is linked with Pipe B.

v2: Addressed review comments of Jani, Nikula
    - Used platform checks for this software workaround for BYT

Signed-off-by: default avatarGaurav K Singh <gaurav.k.singh@intel.com>
Reviewed-by: default avatarJani Nikula <jani.nikula@intel.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
parent bf344e80

drivers/gpu/drm/i915/intel_dsi.c

+17 −5
Original line number Diff line number Diff line
@@ -398,8 +398,10 @@ static bool intel_dsi_get_hw_state(struct intel_encoder *encoder, 
				   enum pipe *pipe)

{

	struct drm_i915_private *dev_priv = encoder->base.dev->dev_private;

	struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);

	struct drm_device *dev = encoder->base.dev;

	enum intel_display_power_domain power_domain;

	u32 port_ctl, func;

	u32 dpi_enabled, func;

	enum port port;



	DRM_DEBUG_KMS("\n");
@@ -409,13 +411,23 @@ static bool intel_dsi_get_hw_state(struct intel_encoder *encoder, 
		return false;



	/* XXX: this only works for one DSI output */

	for_each_dsi_port(port, (1 << PORT_A) | (1 << PORT_C)) {

		port_ctl = I915_READ(MIPI_PORT_CTRL(port));

	for_each_dsi_port(port, intel_dsi->ports) {

		func = I915_READ(MIPI_DSI_FUNC_PRG(port));

		dpi_enabled = I915_READ(MIPI_PORT_CTRL(port)) &

							DPI_ENABLE;



		/* Due to some hardware limitations on BYT, MIPI Port C DPI

		 * Enable bit does not get set. To check whether DSI Port C

		 * was enabled in BIOS, check the Pipe B enable bit

		 */

		if (IS_VALLEYVIEW(dev) && !IS_CHERRYVIEW(dev) &&

		    (port == PORT_C))

			dpi_enabled = I915_READ(PIPECONF(PIPE_B)) &

							PIPECONF_ENABLE;



		if ((port_ctl & DPI_ENABLE) || (func & CMD_MODE_DATA_WIDTH_MASK)) {

		if (dpi_enabled || (func & CMD_MODE_DATA_WIDTH_MASK)) {

			if (I915_READ(MIPI_DEVICE_READY(port)) & DEVICE_READY) {

				*pipe = port == PORT_A ? PIPE_A : PIPE_C;

				*pipe = port == PORT_A ? PIPE_A : PIPE_B;

				return true;

			}

		}