kernel/linux.git/drivers/gpu/drm/msm/dsi, branch v6.1.2

drm/msm/dsi: Prevent signed BPG offsets from bleeding into adjacent bits

2022-12-31T12:32:08+00:00

[ Upstream commit cc84b66be223d36a3d10d59d68ba647e72db3099 ] The bpg_offset array contains negative BPG offsets which fill the full 8 bits of a char thanks to two's complement: this however results in those bits bleeding into the next field when the value is packed into DSC PPS by the drm_dsc_helper function, which only expects range_bpg_offset to contain 6-bit wide values. As a consequence random slices appear corrupted on-screen (tested on a Sony Tama Akatsuki device with sdm845). Use AND operators to limit these two's complement values to 6 bits, similar to the AMD and i915 drivers. Fixes: b9080324d6ca ("drm/msm/dsi: add support for dsc data") Reviewed-by: Abhinav Kumar Reviewed-by: Dmitry Baryshkov Signed-off-by: Marijn Suijten Patchwork: https://patchwork.freedesktop.org/patch/508941/ Link: https://lore.kernel.org/r/20221026182824.876933-11-marijn.suijten@somainline.org Signed-off-by: Dmitry Baryshkov Signed-off-by: Sasha Levin

drm/msm/dsi: Disallow 8 BPC DSC configuration for alternative BPC values

2022-12-31T12:32:07+00:00

[ Upstream commit d053fbc449c47517b1f6516dbce2f917f2a9f51d ] According to the `/* bpc 8 */` comment below only values for a bits_per_component of 8 are currently hardcoded in place. This is further confirmed by downstream sources [1] containing different constants for other BPC values (and different initial_offset too, with an extra dependency on bits_per_pixel). Prevent future mishaps by explicitly disallowing any other bits_per_component value until the right parameters are put in place and tested. [1]: https://git.codelinaro.org/clo/la/platform/vendor/opensource/display-drivers/-/blob/DISPLAY.LA.2.0.r1-08000-WAIPIO.0/msm/sde_dsc_helper.c#L110-139 Fixes: b9080324d6ca ("drm/msm/dsi: add support for dsc data") Reviewed-by: Dmitry Baryshkov Signed-off-by: Marijn Suijten Patchwork: https://patchwork.freedesktop.org/patch/508942/ Link: https://lore.kernel.org/r/20221026182824.876933-9-marijn.suijten@somainline.org Signed-off-by: Dmitry Baryshkov Signed-off-by: Sasha Levin

drm/msm/dsi: Account for DSC's bits_per_pixel having 4 fractional bits

2022-12-31T12:32:07+00:00

[ Upstream commit d2c277c61986942e99680cb67ce26423d0f42f11 ] drm_dsc_config's bits_per_pixel field holds a fractional value with 4 bits, which all panel drivers should adhere to for drm_dsc_pps_payload_pack() to generate a valid payload. All code in the DSI driver here seems to assume that this field doesn't contain any fractional bits, hence resulting in the wrong values being computed. Since none of the calculations leave any room for fractional bits or seem to indicate any possible area of support, disallow such values altogether. calculate_rc_params() in intel_vdsc.c performs an identical bitshift to get at this integer value. Fixes: b9080324d6ca ("drm/msm/dsi: add support for dsc data") Reviewed-by: Abhinav Kumar Reviewed-by: Dmitry Baryshkov Signed-off-by: Marijn Suijten Patchwork: https://patchwork.freedesktop.org/patch/508938/ Link: https://lore.kernel.org/r/20221026182824.876933-8-marijn.suijten@somainline.org Signed-off-by: Dmitry Baryshkov Signed-off-by: Sasha Levin

drm/msm/dsi: Migrate to drm_dsc_compute_rc_parameters()

2022-12-31T12:32:07+00:00

[ Upstream commit c3a1aabce2d4087255de90100c3dad492e7d925c ] As per the FIXME this code is entirely duplicate with what is already provided inside drm_dsc_compute_rc_parameters(), supposedly because that function was yielding "incorrect" results while in reality the panel driver(s?) used for testing were providing incorrect parameters. For example, this code from downstream assumed dsc->bits_per_pixel to contain an integer value, whereas the upstream drm_dsc_config struct stores it with 4 fractional bits. drm_dsc_compute_rc_parameters() already accounts for this feat while the panel driver used for testing [1] wasn't, hence making drm_dsc_compute_rc_parameters() seem like it was returning an incorrect result. Other users of dsc->bits_per_pixel inside dsi_populate_dsc_params() also treat it in the same erroneous way, and will be addressed in a separate patch. In the end, using drm_dsc_compute_rc_parameters() spares both a lot of duplicate code and erratic behaviour. [1]: https://git.linaro.org/people/vinod.koul/kernel.git/commit/?h=topic/pixel3_5.18-rc1&id=1d7d98ad564f1ec69e7525e07418918d90f247a1 Fixes: b9080324d6ca ("drm/msm/dsi: add support for dsc data") Reviewed-by: Abhinav Kumar Signed-off-by: Marijn Suijten Reviewed-by: Dmitry Baryshkov Patchwork: https://patchwork.freedesktop.org/patch/508939/ Link: https://lore.kernel.org/r/20221026182824.876933-7-marijn.suijten@somainline.org Signed-off-by: Dmitry Baryshkov Signed-off-by: Sasha Levin

drm/msm/dsi: Appropriately set dsc->mux_word_size based on bpc

2022-12-31T12:32:07+00:00

[ Upstream commit 0ca870ca304d3449b2ccdc3f0bad9843ff1519f0 ] This field is currently unread but will come into effect when duplicated code below is migrated to call drm_dsc_compute_rc_parameters(), which uses the bpc-dependent value of the local variable mux_words_size in much the same way. The hardcoded constant seems to be a remnant from the `/* bpc 8 */` comment right above, indicating that this group of field assignments is applicable to bpc = 8 exclusively and should probably bail out on different bpc values, until constants for other bpc values are added (or the current ones are confirmed to be correct across multiple bpc's). Fixes: b9080324d6ca ("drm/msm/dsi: add support for dsc data") Reviewed-by: Abhinav Kumar Reviewed-by: Dmitry Baryshkov Signed-off-by: Marijn Suijten Patchwork: https://patchwork.freedesktop.org/patch/508943/ Link: https://lore.kernel.org/r/20221026182824.876933-6-marijn.suijten@somainline.org Signed-off-by: Dmitry Baryshkov Signed-off-by: Sasha Levin

drm/msm/dsi: Reuse earlier computed dsc->slice_chunk_size

2022-12-31T12:32:07+00:00

[ Upstream commit e443459e2e6b8e0d3187dd0d09ef7fcea87531d2 ] dsi_populate_dsc_params() is called prior to dsi_update_dsc_timing() and already computes a value for slice_chunk_size, whose value doesn't need to be recomputed and re-set here. Fixes: 08802f515c3c ("drm/msm/dsi: Add support for DSC configuration") Reviewed-by: Abhinav Kumar Reviewed-by: Dmitry Baryshkov Signed-off-by: Marijn Suijten Patchwork: https://patchwork.freedesktop.org/patch/508934/ Link: https://lore.kernel.org/r/20221026182824.876933-5-marijn.suijten@somainline.org Signed-off-by: Dmitry Baryshkov Signed-off-by: Sasha Levin

drm/msm/dsi: Use DIV_ROUND_UP instead of conditional increment on modulo

2022-12-31T12:32:07+00:00

[ Upstream commit 1e8196103bd02a396b45c8f6188541634a47fce2 ] This exact same math is used to compute bytes_in_slice above in dsi_update_dsc_timing(), also used to fill slice_chunk_size. Fixes: b9080324d6ca ("drm/msm/dsi: add support for dsc data") Reviewed-by: Abhinav Kumar Reviewed-by: Dmitry Baryshkov Signed-off-by: Marijn Suijten Patchwork: https://patchwork.freedesktop.org/patch/508935/ Link: https://lore.kernel.org/r/20221026182824.876933-4-marijn.suijten@somainline.org Signed-off-by: Dmitry Baryshkov Signed-off-by: Sasha Levin

drm/msm/dsi: Remove repeated calculation of slice_per_intf

2022-12-31T12:32:07+00:00

[ Upstream commit 170ffca836dd9f1a0219c4f67554d408fa2b5912 ] slice_per_intf is already computed for intf_width, which holds the same value as hdisplay. Fixes: 08802f515c3c ("drm/msm/dsi: Add support for DSC configuration") Reviewed-by: Bjorn Andersson Reviewed-by: Konrad Dybcio Reviewed-by: Abhinav Kumar Reviewed-by: Vinod Koul Reviewed-by: Dmitry Baryshkov Signed-off-by: Marijn Suijten Patchwork: https://patchwork.freedesktop.org/patch/508933/ Link: https://lore.kernel.org/r/20221026182824.876933-3-marijn.suijten@somainline.org Signed-off-by: Dmitry Baryshkov Signed-off-by: Sasha Levin

drm/msm/dsi: Remove useless math in DSC calculations

2022-12-31T12:32:07+00:00

[ Upstream commit 01a907980e0be3310f18c7d4955968f3b28e7147 ] Multiplying a value by 2 and adding 1 to it always results in a value that is uneven, and that 1 gets truncated immediately when performing integer division by 2 again. There is no "rounding" possible here. After that target_bpp_x16 is used to store a multiplication of bits_per_pixel by 16 which is only ever read to immediately be divided by 16 again, and is elided in much the same way. Fixes: b9080324d6ca ("drm/msm/dsi: add support for dsc data") Reviewed-by: Abhinav Kumar Reviewed-by: Dmitry Baryshkov Signed-off-by: Marijn Suijten Patchwork: https://patchwork.freedesktop.org/patch/508932/ Link: https://lore.kernel.org/r/20221026182824.876933-2-marijn.suijten@somainline.org Signed-off-by: Dmitry Baryshkov Signed-off-by: Sasha Levin

drm/msm/dsi: fix memory corruption with too many bridges

2022-09-30T16:57:53+00:00

Add the missing sanity check on the bridge counter to avoid corrupting data beyond the fixed-sized bridge array in case there are ever more than eight bridges. Fixes: a689554ba6ed ("drm/msm: Initial add DSI connector support") Cc: stable@vger.kernel.org # 4.1 Signed-off-by: Johan Hovold Tested-by: Kuogee Hsieh Reviewed-by: Kuogee Hsieh Reviewed-by: Dmitry Baryshkov Patchwork: https://patchwork.freedesktop.org/patch/502668/ Link: https://lore.kernel.org/r/20220913085320.8577-4-johan+linaro@kernel.org Signed-off-by: Abhinav Kumar