This is a note to let you know that I've just added the patch titled i915: Set ddi_pll_sel in DP MST path to the 4.2-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: i915-set-ddi_pll_sel-in-dp-mst-path.patch and it can be found in the queue-4.2 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 6fa2d197936ba0b8936e813d0adecefac160062b Mon Sep 17 00:00:00 2001 From: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@xxxxxxxxx> Date: Mon, 31 Aug 2015 11:23:28 +0300 Subject: i915: Set ddi_pll_sel in DP MST path MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@xxxxxxxxx> commit 6fa2d197936ba0b8936e813d0adecefac160062b upstream. The DP MST encoder config function never sets ddi_pll_sel, even though its value is programmed in its ->pre_enable() hook. That used to work because a new pipe_config was kzalloc'ed at every modeset, and the value of zero selects the highest clock for the PLL. Starting with the commit below, the value of ddi_pll_sel is preserved through modesets, and since the correct value wasn't properly setup by the MST code, it could lead to warnings and blank screens. commit 8504c74c7ae48b4b8ed1f1c0acf67482a7f45c93 Author: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@xxxxxxxxx> Date: Fri May 15 11:51:50 2015 +0300 drm/i915: Preserve ddi_pll_sel when allocating new pipe_config Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=91628 Cc: Timo Aaltonen <tjaalton@xxxxxxxxxx> Cc: Luciano Coelho <luciano.coelho@xxxxxxxxx> Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@xxxxxxxxx> Reviewed-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/i915/intel_dp.c | 2 +- drivers/gpu/drm/i915/intel_dp_mst.c | 5 +++++ drivers/gpu/drm/i915/intel_drv.h | 1 + 3 files changed, 7 insertions(+), 1 deletion(-) --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -1134,7 +1134,7 @@ skl_edp_set_pll_config(struct intel_crtc pipe_config->dpll_hw_state.ctrl1 = ctrl1; } -static void +void hsw_dp_set_ddi_pll_sel(struct intel_crtc_state *pipe_config) { memset(&pipe_config->dpll_hw_state, 0, --- a/drivers/gpu/drm/i915/intel_dp_mst.c +++ b/drivers/gpu/drm/i915/intel_dp_mst.c @@ -33,6 +33,7 @@ static bool intel_dp_mst_compute_config(struct intel_encoder *encoder, struct intel_crtc_state *pipe_config) { + struct drm_device *dev = encoder->base.dev; struct intel_dp_mst_encoder *intel_mst = enc_to_mst(&encoder->base); struct intel_digital_port *intel_dig_port = intel_mst->primary; struct intel_dp *intel_dp = &intel_dig_port->dp; @@ -97,6 +98,10 @@ static bool intel_dp_mst_compute_config( &pipe_config->dp_m_n); pipe_config->dp_m_n.tu = slots; + + if (IS_HASWELL(dev) || IS_BROADWELL(dev)) + hsw_dp_set_ddi_pll_sel(pipe_config); + return true; } --- a/drivers/gpu/drm/i915/intel_drv.h +++ b/drivers/gpu/drm/i915/intel_drv.h @@ -1194,6 +1194,7 @@ void intel_edp_drrs_disable(struct intel void intel_edp_drrs_invalidate(struct drm_device *dev, unsigned frontbuffer_bits); void intel_edp_drrs_flush(struct drm_device *dev, unsigned frontbuffer_bits); +void hsw_dp_set_ddi_pll_sel(struct intel_crtc_state *pipe_config); /* intel_dp_mst.c */ int intel_dp_mst_encoder_init(struct intel_digital_port *intel_dig_port, int conn_id); Patches currently in stable-queue which might be from ander.conselvan.de.oliveira@xxxxxxxxx are queue-4.2/i915-set-ddi_pll_sel-in-dp-mst-path.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html