On Thu, 2025-08-28 at 15:20 +0300, Jani Nikula wrote:
> Prefer generic poll helpers over i915 custom helpers.
>
> The functional change is losing the exponentially growing sleep of
> wait_for(), which used to be 10, 20, 40, ..., 640, and 1280 us.
>
> Use an arbitrary constant 500 us sleep instead. The timeout remains
> at
> 100 ms.
>
> Signed-off-by: Jani Nikula <jani.nik...@intel.com>
Reviewed-by: Jouni Högander <jouni.hogan...@intel.com>
> ---
> drivers/gpu/drm/i915/display/intel_vblank.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_vblank.c
> b/drivers/gpu/drm/i915/display/intel_vblank.c
> index 46d6db5fed11..c15234c1d96e 100644
> --- a/drivers/gpu/drm/i915/display/intel_vblank.c
> +++ b/drivers/gpu/drm/i915/display/intel_vblank.c
> @@ -3,6 +3,8 @@
> * Copyright © 2022-2023 Intel Corporation
> */
>
> +#include <linux/iopoll.h>
> +
> #include <drm/drm_vblank.h>
>
> #include "i915_drv.h"
> @@ -493,9 +495,14 @@ static void wait_for_pipe_scanline_moving(struct
> intel_crtc *crtc, bool state)
> {
> struct intel_display *display = to_intel_display(crtc);
> enum pipe pipe = crtc->pipe;
> + bool is_moving;
> + int ret;
>
> /* Wait for the display line to settle/start moving */
> - if (wait_for(pipe_scanline_is_moving(display, pipe) ==
> state, 100))
> + ret = poll_timeout_us(is_moving =
> pipe_scanline_is_moving(display, pipe),
> + is_moving == state,
> + 500, 100 * 1000, false);
> + if (ret)
> drm_err(display->drm,
> "pipe %c scanline %s wait timed out\n",
> pipe_name(pipe), str_on_off(state));
