On Thu, 2025-08-28 at 15:21 +0300, Jani Nikula wrote:
> Unify on using poll_timeout_us() throughout instead of mixing with
> readx_poll_timeout(). While the latter can be ever so slightly
> simpler,
> they are both complicated enough that it's better to unify on one
> approach only.
>
> While at it, better separate the handling of error returns from
> drm_dp_dpcd_readb() and the actual status byte. This is best achieved
> by
> inlining the read_fec_detected_status() function, and switching to
> drm_dp_dpcd_read_byte().
>
> v2: Use drm_dp_dpcd_read_byte() (Imre)
>
> Cc: Imre Deak <imre.d...@intel.com>
> Signed-off-by: Jani Nikula <jani.nik...@intel.com>
Reviewed-by: Jouni Högander <jouni.hogan...@intel.com>
> ---
> drivers/gpu/drm/i915/display/intel_ddi.c | 32 ++++++++--------------
> --
> 1 file changed, 11 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c
> b/drivers/gpu/drm/i915/display/intel_ddi.c
> index 4e4ea3a0ff83..46017091bb0b 100644
> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> @@ -2340,34 +2340,24 @@ static void
> intel_dp_sink_set_fec_ready(struct intel_dp *intel_dp,
> drm_dbg_kms(display->drm, "Failed to clear FEC
> detected flags\n");
> }
>
> -static int read_fec_detected_status(struct drm_dp_aux *aux)
> -{
> - int ret;
> - u8 status;
> -
> - ret = drm_dp_dpcd_readb(aux, DP_FEC_STATUS, &status);
> - if (ret < 0)
> - return ret;
> -
> - return status;
> -}
> -
> static int wait_for_fec_detected(struct drm_dp_aux *aux, bool
> enabled)
> {
> struct intel_display *display = to_intel_display(aux-
> >drm_dev);
> int mask = enabled ? DP_FEC_DECODE_EN_DETECTED :
> DP_FEC_DECODE_DIS_DETECTED;
> - int status;
> - int err;
> + u8 status = 0;
> + int ret, err;
>
> - err = readx_poll_timeout(read_fec_detected_status, aux,
> status,
> - status & mask || status < 0,
> - 10000, 200000);
> + ret = poll_timeout_us(err = drm_dp_dpcd_read_byte(aux,
> DP_FEC_STATUS, &status),
> + err || (status & mask),
> + 10 * 1000, 200 * 1000, false);
>
> - if (err || status < 0) {
> + /* Either can be non-zero, but not both */
> + ret = ret ?: err;
> + if (ret) {
> drm_dbg_kms(display->drm,
> - "Failed waiting for FEC %s to get
> detected: %d (status %d)\n",
> - str_enabled_disabled(enabled), err,
> status);
> - return err ? err : status;
> + "Failed waiting for FEC %s to get
> detected: %d (status 0x%02x)\n",
> + str_enabled_disabled(enabled), ret,
> status);
> + return ret;
> }
>
> return 0;
