From: Rob Clark robdclark@chromium.org
Mark power domains that may be enabled by bootloader, and which should not be disabled until a driver takes them over.
This keeps efifb alive until the real driver can be probed. In a distro kernel, the driver will most likely built as a module, and not probed until we get to userspace (after late_initcall)
Signed-off-by: Rob Clark robdclark@chromium.org --- drivers/base/power/domain.c | 10 ++++++++++ drivers/clk/qcom/dispcc-sdm845.c | 2 +- drivers/clk/qcom/gdsc.c | 5 +++++ drivers/clk/qcom/gdsc.h | 1 + include/linux/pm_domain.h | 4 ++++ 5 files changed, 21 insertions(+), 1 deletion(-)
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 33c30c1e6a30..513a8655fbd7 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -537,6 +537,16 @@ static int genpd_power_off(struct generic_pm_domain *genpd, bool one_dev_on, not_suspended++; }
+ /* + * If the power domain is enabled by the bootloader (for example + * display enabled by bootloader), but no devices attached yet + * (perhaps because driver built as kernel module), then do not + * suspend. + */ + if ((genpd->flags & GENPD_FLAG_INHERIT_BL) && + list_empty(&genpd->dev_list)) + not_suspended++; + if (not_suspended > 1 || (not_suspended == 1 && !one_dev_on)) return -EBUSY;
diff --git a/drivers/clk/qcom/dispcc-sdm845.c b/drivers/clk/qcom/dispcc-sdm845.c index 40d7e0ab4340..1d9365ac2315 100644 --- a/drivers/clk/qcom/dispcc-sdm845.c +++ b/drivers/clk/qcom/dispcc-sdm845.c @@ -575,7 +575,7 @@ static struct gdsc mdss_gdsc = { .name = "mdss_gdsc", }, .pwrsts = PWRSTS_OFF_ON, - .flags = HW_CTRL | POLL_CFG_GDSCR, + .flags = HW_CTRL | POLL_CFG_GDSCR | INHERIT_BL, };
static struct clk_regmap *disp_cc_sdm845_clocks[] = { diff --git a/drivers/clk/qcom/gdsc.c b/drivers/clk/qcom/gdsc.c index a250f59708d8..4639fbeb9a7f 100644 --- a/drivers/clk/qcom/gdsc.c +++ b/drivers/clk/qcom/gdsc.c @@ -331,6 +331,11 @@ static int gdsc_init(struct gdsc *sc) if ((sc->flags & VOTABLE) && on) gdsc_enable(&sc->pd);
+ if ((sc->flags & INHERIT_BL) && on) { + pr_debug("gdsc: %s is enabled from bootloader!\n", sc->pd.name); + sc->pd.flags |= GENPD_FLAG_INHERIT_BL; + } + /* If ALWAYS_ON GDSCs are not ON, turn them ON */ if (sc->flags & ALWAYS_ON) { if (!on) diff --git a/drivers/clk/qcom/gdsc.h b/drivers/clk/qcom/gdsc.h index 64cdc8cf0d4d..c6fe56247399 100644 --- a/drivers/clk/qcom/gdsc.h +++ b/drivers/clk/qcom/gdsc.h @@ -49,6 +49,7 @@ struct gdsc { #define AON_RESET BIT(4) #define POLL_CFG_GDSCR BIT(5) #define ALWAYS_ON BIT(6) +#define INHERIT_BL BIT(7) struct reset_controller_dev *rcdev; unsigned int *resets; unsigned int reset_count; diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h index 91d9bf497071..5e421afcf6f3 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h @@ -55,6 +55,9 @@ * * GENPD_FLAG_RPM_ALWAYS_ON: Instructs genpd to always keep the PM domain * powered on except for system suspend. + * + * GENPD_FLAG_INHERIT_BL: The bootloader has already enabled this power + * domain. */ #define GENPD_FLAG_PM_CLK (1U << 0) #define GENPD_FLAG_IRQ_SAFE (1U << 1) @@ -62,6 +65,7 @@ #define GENPD_FLAG_ACTIVE_WAKEUP (1U << 3) #define GENPD_FLAG_CPU_DOMAIN (1U << 4) #define GENPD_FLAG_RPM_ALWAYS_ON (1U << 5) +#define GENPD_FLAG_INHERIT_BL (1U << 6)
enum gpd_status { GPD_STATE_ACTIVE = 0, /* PM domain is active */