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mirror of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2025-09-04 20:19:47 +08:00
linux/drivers/gpu/drm/msm/dsi
Krzysztof Kozlowski 8a48e35bec drm/msm/dsi/dsi_phy_10nm: Fix missing initial VCO rate
Driver unconditionally saves current state on first init in
dsi_pll_10nm_init(), but does not save the VCO rate, only some of the
divider registers.  The state is then restored during probe/enable via
msm_dsi_phy_enable() -> msm_dsi_phy_pll_restore_state() ->
dsi_10nm_pll_restore_state().

Restoring calls dsi_pll_10nm_vco_set_rate() with
pll_10nm->vco_current_rate=0, which basically overwrites existing rate of
VCO and messes with clock hierarchy, by setting frequency to 0 to clock
tree.  This makes anyway little sense - VCO rate was not saved, so
should not be restored.

If PLL was not configured configure it to minimum rate to avoid glitches
and configuring entire in clock hierarchy to 0 Hz.

Suggested-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Link: https://lore.kernel.org/r/sz4kbwy5nwsebgf64ia7uq4ee7wbsa5uy3xmlqwcstsbntzcov@ew3dcyjdzmi2/
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Fixes: a4ccc37693 ("drm/msm/dsi_pll_10nm: restore VCO rate during
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/654796/
Link: https://lore.kernel.org/r/20250520111325.92352-2-krzysztof.kozlowski@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
2025-06-09 08:33:41 +03:00
..
phy drm/msm/dsi/dsi_phy_10nm: Fix missing initial VCO rate 2025-06-09 08:33:41 +03:00
dsi_cfg.c drm/msm/dsi: add DSI support for SA8775P 2025-05-02 03:54:03 +03:00
dsi_cfg.h drm/msm/dsi: add DSI support for SA8775P 2025-05-02 03:54:03 +03:00
dsi_host.c drm/msm/dsi: Add check for devm_kstrdup() 2025-02-26 12:15:49 +02:00
dsi_manager.c drm/msm/dsi: convert to devm_drm_bridge_alloc() API 2025-04-29 11:21:24 +02:00
dsi.c Get rid of 'remove_new' relic from platform driver struct 2024-12-01 15:12:43 -08:00
dsi.h drm/msm/dsi: parse vsync source from device tree 2024-06-24 19:41:05 +03:00