Re: [PATCH v2 4/7] drm/i915/cdclk: use intel_de_wait_custom() instead of wait_for_us()

[Gustavo Sousa <gustavo.sousa@intel.com>]

Quoting Jani Nikula (2025-07-31 07:05:11-03:00)
>Prefer the register read specific wait function over i915 wait_for_us().
>
>Signed-off-by: Jani Nikula <jani.nikula@intel.com>

Reviewed-by: Gustavo Sousa <gustavo.sousa@intel.com>

>---
> drivers/gpu/drm/i915/display/intel_cdclk.c | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
>diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.c b/drivers/gpu/drm/i915/display/intel_cdclk.c
>index 228aa64c1349..2a2d6714e4f4 100644
>--- a/drivers/gpu/drm/i915/display/intel_cdclk.c
>+++ b/drivers/gpu/drm/i915/display/intel_cdclk.c
>@@ -903,8 +903,10 @@ static void bdw_set_cdclk(struct intel_display *display,
>          * According to the spec, it should be enough to poll for this 1 us.
>          * However, extensive testing shows that this can take longer.
>          */
>-        if (wait_for_us(intel_de_read(display, LCPLL_CTL) &
>-                        LCPLL_CD_SOURCE_FCLK_DONE, 100))
>+        ret = intel_de_wait_custom(display, LCPLL_CTL,
>+                                   LCPLL_CD_SOURCE_FCLK_DONE, LCPLL_CD_SOURCE_FCLK_DONE,
>+                                   100, 0, NULL);
>+        if (ret)
>                 drm_err(display->drm, "Switching to FCLK failed\n");
> 
>         intel_de_rmw(display, LCPLL_CTL,
>@@ -913,8 +915,10 @@ static void bdw_set_cdclk(struct intel_display *display,
>         intel_de_rmw(display, LCPLL_CTL,
>                      LCPLL_CD_SOURCE_FCLK, 0);
> 
>-        if (wait_for_us((intel_de_read(display, LCPLL_CTL) &
>-                         LCPLL_CD_SOURCE_FCLK_DONE) == 0, 1))
>+        ret = intel_de_wait_custom(display, LCPLL_CTL,
>+                                   LCPLL_CD_SOURCE_FCLK_DONE, 0,
>+                                   1, 0, NULL);
>+        if (ret)
>                 drm_err(display->drm, "Switching back to LCPLL failed\n");
> 
>         intel_pcode_write(display->drm, HSW_PCODE_DE_WRITE_FREQ_REQ,
>-- 
>2.39.5
>