On Thu, 2022-09-22 at 10:59 +0300, Jouni Högander wrote:
> Current PSR code is supposed to use TRANSCODER_EDP to force 0 shift for
> bits in PSR_IMR/IIR registers:
>
> /*
> * gen12+ has registers relative to transcoder and one per transcoder
> * using the same bit definition: handle it as TRANSCODER_EDP to force
> * 0 shift in bit definition
> */
>
> At the time of writing the code assumption "TRANSCODER_EDP == 0" was made.
> This is not the case and all fields in PSR_IMR and PSR_IIR are shifted
> incorrectly if DISPLAY_VER >= 12.
From where are you getting that TRANSCODER_EDP == 0?
enum pipe {
INVALID_PIPE = -1,
PIPE_A = 0,
PIPE_B,
PIPE_C,
PIPE_D,
_PIPE_EDP,
I915_MAX_PIPES = _PIPE_EDP
};
#define pipe_name(p) ((p) + 'A')
enum transcoder {
INVALID_TRANSCODER = -1,
/*
* The following transcoders have a 1:1 transcoder -> pipe mapping,
* keep their values fixed: the code assumes that TRANSCODER_A=0, the
* rest have consecutive values and match the enum values of the pipes
* they map to.
*/
TRANSCODER_A = PIPE_A,
TRANSCODER_B = PIPE_B,
TRANSCODER_C = PIPE_C,
TRANSCODER_D = PIPE_D,
/*
* The following transcoders can map to any pipe, their enum value
* doesn't need to stay fixed.
*/
TRANSCODER_EDP,
https://cgit.freedesktop.org/drm-tip/tree/drivers/gpu/drm/i915/display/intel_display.h#n87
>
> Fix this by using TRANSCODER_EDP definition instead of 0. Even thought
> TRANSCODER_EDP doesn't exist in display_ver >= 12 doing it this way keeps
> code clean and readable.
trans_shift = 0 is fine, we needed this because display12+ splited from a
single register with all transcoder to one register per transcoder.
>
> v2: Improve commit message (José)
>
> Cc: Mika Kahola <[email protected]>
> Cc: José Roberto de Souza <[email protected]>
>
> Signed-off-by: Jouni Högander <[email protected]>
> ---
> drivers/gpu/drm/i915/display/intel_psr.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_psr.c
> b/drivers/gpu/drm/i915/display/intel_psr.c
> index 9def8d9fade6..9ecf1a9a1120 100644
> --- a/drivers/gpu/drm/i915/display/intel_psr.c
> +++ b/drivers/gpu/drm/i915/display/intel_psr.c
> @@ -129,7 +129,7 @@ static void psr_irq_control(struct intel_dp *intel_dp)
> * 0 shift in bit definition
> */
> if (DISPLAY_VER(dev_priv) >= 12) {
> - trans_shift = 0;
> + trans_shift = TRANSCODER_EDP;
> imr_reg = TRANS_PSR_IMR(intel_dp->psr.transcoder);
> } else {
> trans_shift = intel_dp->psr.transcoder;
> @@ -195,7 +195,7 @@ void intel_psr_irq_handler(struct intel_dp *intel_dp, u32
> psr_iir)
> i915_reg_t imr_reg;
>
> if (DISPLAY_VER(dev_priv) >= 12) {
> - trans_shift = 0;
> + trans_shift = TRANSCODER_EDP;
> imr_reg = TRANS_PSR_IMR(intel_dp->psr.transcoder);
> } else {
> trans_shift = intel_dp->psr.transcoder;
> @@ -1197,7 +1197,7 @@ static bool psr_interrupt_error_check(struct intel_dp
> *intel_dp)
> if (DISPLAY_VER(dev_priv) >= 12) {
> val = intel_de_read(dev_priv,
> TRANS_PSR_IIR(intel_dp->psr.transcoder));
> - val &= EDP_PSR_ERROR(0);
> + val &= EDP_PSR_ERROR(TRANSCODER_EDP);
> } else {
> val = intel_de_read(dev_priv, EDP_PSR_IIR);
> val &= EDP_PSR_ERROR(intel_dp->psr.transcoder);
