Commit a975fea5 authored by Jani Nikula's avatar Jani Nikula
Browse files

drm/i915/power: use intel_de_wait_for_clear() instead of wait_for() 



Prefer the register read specific wait function over i915 wait_for_us().

The existing condition is quite complicated. Simplify by checking for
requesters first, and determine timeout based on that. Refresh
requesters in case of timeouts, should one have popped up during the
wait. The downside is that this does not cut the wait short if
requesters show up *during* the wait, but we're talking about 1 ms so
shouldn't be an issue.

v2: Refresh requesters only if there were none before (Imre)

Cc: Imre Deak <imre.deak@intel.com>
Reviewed-by: default avatarImre Deak <imre.deak@intel.com>
Link: https://lore.kernel.org/r/20250626192632.2330349-1-jani.nikula@intel.com


Signed-off-by: default avatarJani Nikula <jani.nikula@intel.com>
parent 95f2dec0

drivers/gpu/drm/i915/display/intel_display_power_well.c

+11 −5
Original line number Diff line number Diff line
@@ -320,8 +320,8 @@ static void hsw_wait_for_power_well_disable(struct intel_display *display, 
{

	const struct i915_power_well_regs *regs = power_well->desc->ops->regs;

	int pw_idx = i915_power_well_instance(power_well)->hsw.idx;

	bool disabled;

	u32 reqs;

	int ret;



	/*

	 * Bspec doesn't require waiting for PWs to get disabled, but still do
@@ -332,12 +332,18 @@ static void hsw_wait_for_power_well_disable(struct intel_display *display, 
	 * Skip the wait in case any of the request bits are set and print a

	 * diagnostic message.

	 */

	wait_for((disabled = !(intel_de_read(display, regs->driver) &

			       HSW_PWR_WELL_CTL_STATE(pw_idx))) ||

		 (reqs = hsw_power_well_requesters(display, regs, pw_idx)), 1);

	if (disabled)

	reqs = hsw_power_well_requesters(display, regs, pw_idx);



	ret = intel_de_wait_for_clear(display, regs->driver,

				      HSW_PWR_WELL_CTL_STATE(pw_idx),

				      reqs ? 0 : 1);

	if (!ret)

		return;



	/* Refresh requesters in case they popped up during the wait. */

	if (!reqs)

		reqs = hsw_power_well_requesters(display, regs, pw_idx);



	drm_dbg_kms(display->drm,

		    "%s forced on (bios:%d driver:%d kvmr:%d debug:%d)\n",

		    intel_power_well_name(power_well),