Re: [Intel-gfx] [PATCH 02/14] drm/i915: Clean up M/N register defines

Jani Nikula
2022-01-27T11:17:30Z

On Thu, 27 Jan 2022, Ville Syrjala <ville.syrjala@linux.intel.com> wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> Use REG_GENMASK() & co. for the M/N register values. There are
> also a lot of weird unused defines (eg. *_OFFSET) we can just
> throw out.
>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
> drivers/gpu/drm/i915/display/intel_display.c | 10 ++++-----
> drivers/gpu/drm/i915/i915_reg.h | 22 +++-----------------
> 2 files changed, 8 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index f76faa195cb9..d91164d1eb92 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -3865,11 +3865,11 @@ static void intel_get_m_n(struct drm_i915_private *i915,
> i915_reg_t data_m_reg, i915_reg_t data_n_reg,
> i915_reg_t link_m_reg, i915_reg_t link_n_reg)
> {
> - m_n->link_m = intel_de_read(i915, link_m_reg);
> - m_n->link_n = intel_de_read(i915, link_n_reg);
> - m_n->gmch_m = intel_de_read(i915, data_m_reg) & ~TU_SIZE_MASK;
> - m_n->gmch_n = intel_de_read(i915, data_n_reg);
> - m_n->tu = ((intel_de_read(i915, data_m_reg) & TU_SIZE_MASK) >> TU_SIZE_SHIFT) + 1;
> + m_n->link_m = intel_de_read(i915, link_m_reg) & DATA_LINK_M_N_MASK;
> + m_n->link_n = intel_de_read(i915, link_n_reg) & DATA_LINK_M_N_MASK;
> + m_n->gmch_m = intel_de_read(i915, data_m_reg) & DATA_LINK_M_N_MASK;
> + m_n->gmch_n = intel_de_read(i915, data_n_reg) & DATA_LINK_M_N_MASK;
> + m_n->tu = REG_FIELD_GET(TU_SIZE_MASK, intel_de_read(i915, data_m_reg)) + 1;

The commit message might mention we throw some bits away while reading.

A follow-up could perhasps axe the double read of the data_m_reg, but
*shrug*.

Reviewed-by: Jani Nikula <jani.nikula@intel.com>

> }
>
> static void intel_pch_transcoder_get_m_n(struct intel_crtc *crtc,
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 2e4dd9db63fe..ec48406eb37a 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -5209,16 +5209,14 @@ enum {
> #define _PIPEB_DATA_M_G4X 0x71050
>
> /* Transfer unit size for display port - 1, default is 0x3f (for TU size 64) */
> -#define TU_SIZE(x) (((x) - 1) << 25) /* default size 64 */
> -#define TU_SIZE_SHIFT 25
> -#define TU_SIZE_MASK (0x3f << 25)
> +#define TU_SIZE_MASK REG_GENMASK(30, 25)
> +#define TU_SIZE(x) REG_FIELD_PREP(TU_SIZE_MASK, (x) - 1) /* default size 64 */
>
> -#define DATA_LINK_M_N_MASK (0xffffff)
> +#define DATA_LINK_M_N_MASK REG_GENMASK(23, 0)
> #define DATA_LINK_N_MAX (0x800000)
>
> #define _PIPEA_DATA_N_G4X 0x70054
> #define _PIPEB_DATA_N_G4X 0x71054
> -#define PIPE_GMCH_DATA_N_MASK (0xffffff)
>
> /*
> * Computing Link M and N values for the Display Port link
> @@ -5233,11 +5231,8 @@ enum {
>
> #define _PIPEA_LINK_M_G4X 0x70060
> #define _PIPEB_LINK_M_G4X 0x71060
> -#define PIPEA_DP_LINK_M_MASK (0xffffff)
> -
> #define _PIPEA_LINK_N_G4X 0x70064
> #define _PIPEB_LINK_N_G4X 0x71064
> -#define PIPEA_DP_LINK_N_MASK (0xffffff)
>
> #define PIPE_DATA_M_G4X(pipe) _MMIO_PIPE(pipe, _PIPEA_DATA_M_G4X, _PIPEB_DATA_M_G4X)
> #define PIPE_DATA_N_G4X(pipe) _MMIO_PIPE(pipe, _PIPEA_DATA_N_G4X, _PIPEB_DATA_N_G4X)
> @@ -6840,24 +6835,13 @@ enum {
>
>
> #define _PIPEA_DATA_M1 0x60030
> -#define PIPE_DATA_M1_OFFSET 0
> #define _PIPEA_DATA_N1 0x60034
> -#define PIPE_DATA_N1_OFFSET 0
> -
> #define _PIPEA_DATA_M2 0x60038
> -#define PIPE_DATA_M2_OFFSET 0
> #define _PIPEA_DATA_N2 0x6003c
> -#define PIPE_DATA_N2_OFFSET 0
> -
> #define _PIPEA_LINK_M1 0x60040
> -#define PIPE_LINK_M1_OFFSET 0
> #define _PIPEA_LINK_N1 0x60044
> -#define PIPE_LINK_N1_OFFSET 0
> -
> #define _PIPEA_LINK_M2 0x60048
> -#define PIPE_LINK_M2_OFFSET 0
> #define _PIPEA_LINK_N2 0x6004c
> -#define PIPE_LINK_N2_OFFSET 0
>
> /* PIPEB timing regs are same start from 0x61000 */

--
Jani Nikula, Intel Open Source Graphics Center