From 0661ee1d650facefdf61401c7d00eb96fad40b10 Mon Sep 17 00:00:00 2001 From: Jagadeesh Kona Date: Mon, 27 Apr 2026 12:08:55 +0530 Subject: [PATCH] clk: qcom: gdsc: Add custom disable callback for GX GDSC MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The GX GDSC is a special power domain that should only be disabled by OS during GMU recovery. In all other scenarios, the GMU firmware is responsible for handling its disable sequence, and OS must not interfere. During the resume_noirq() phase of system resume, the GenPD framework enables all power domains and later disables them in the complete() phase if there are no active votes from OS. This behavior can incorrectly disable the GX GDSC while the GMU firmware is still using it. To prevent this, implement a custom disable callback for GX GDSC that relies on GenPD’s synced_poweroff flag. The GMU driver sets this flag only during recovery, allowing OS to explicitly disable GX GDSC in hardware in that case. In all other situations, the disable callback will avoid touching GX GDSC hardware. Signed-off-by: Jagadeesh Kona Signed-off-by: Taniya Das Reviewed-by: Konrad Dybcio Link: https://lore.kernel.org/r/20260427-gfx-clk-fixes-v2-1-797e54b3d464@oss.qualcomm.com Signed-off-by: Bjorn Andersson --- drivers/clk/qcom/gdsc.c | 22 ++++++++++++++++++++++ drivers/clk/qcom/gdsc.h | 1 + 2 files changed, 23 insertions(+) diff --git a/drivers/clk/qcom/gdsc.c b/drivers/clk/qcom/gdsc.c index ee5f86ca50cb..f419a28f616b 100644 --- a/drivers/clk/qcom/gdsc.c +++ b/drivers/clk/qcom/gdsc.c @@ -708,3 +708,25 @@ int gdsc_gx_do_nothing_enable(struct generic_pm_domain *domain) return ret; } EXPORT_SYMBOL_GPL(gdsc_gx_do_nothing_enable); + +/* + * GX GDSC is a special power domain. Normally, its disable sequence + * is managed by the GMU firmware, and high level OS must not attempt + * to disable it. The only exception is during GMU recovery, where the + * GMU driver can set GenPD’s synced_poweroff flag to allow explicitly + * disable GX GDSC in hardware. + */ +int gdsc_gx_disable(struct generic_pm_domain *domain) +{ + struct gdsc *sc = domain_to_gdsc(domain); + + if (domain->synced_poweroff) + return gdsc_disable(domain); + + /* Remove parent-supply placed in enable */ + if (sc->rsupply) + return regulator_disable(sc->rsupply); + + return 0; +} +EXPORT_SYMBOL_GPL(gdsc_gx_disable); diff --git a/drivers/clk/qcom/gdsc.h b/drivers/clk/qcom/gdsc.h index 92ff6bcce7b1..2f9665b664e6 100644 --- a/drivers/clk/qcom/gdsc.h +++ b/drivers/clk/qcom/gdsc.h @@ -93,6 +93,7 @@ int gdsc_register(struct gdsc_desc *desc, struct reset_controller_dev *, struct regmap *); void gdsc_unregister(struct gdsc_desc *desc); int gdsc_gx_do_nothing_enable(struct generic_pm_domain *domain); +int gdsc_gx_disable(struct generic_pm_domain *domain); #else static inline int gdsc_register(struct gdsc_desc *desc, struct reset_controller_dev *rcdev,