Re: [PATCH v2] drm/dp: move intel_dp_vsc_sdp_pack() to generic helper

Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx> · Tue, 20 Feb 2024 10:53:15 -0800

On 2/20/2024 10:49 AM, Dmitry Baryshkov wrote:
On Thu, 15 Feb 2024 at 21:08, Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx> wrote:

intel_dp_vsc_sdp_pack() can be re-used by other DRM drivers as well.
Lets move this to drm_dp_helper to achieve this.

changes in v2:
         - rebased on top of drm-tip

Acked-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>

v1 had an explicit comment before the ack:


Yes, I remember the comment. I did not make any changes to v2 other than 
just rebasing it on drm-tip to get the ack from i915 folks.

    From my side, with the promise of the size fixup.

However I observe neither a second patch removing the size argument
nor it being dropped as a part of this patch.


Yes, now that in v2 we got the ack for this patch, I can spin a v3 with 
the addition of the next patch to remove the size OR as another series 
so as to not block the main series which needs this patch.

I would prefer the latter.

Signed-off-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
---
  drivers/gpu/drm/display/drm_dp_helper.c | 78 +++++++++++++++++++++++++
  drivers/gpu/drm/i915/display/intel_dp.c | 71 +---------------------
  include/drm/display/drm_dp_helper.h     |  3 +
  3 files changed, 83 insertions(+), 69 deletions(-)

diff --git a/drivers/gpu/drm/display/drm_dp_helper.c b/drivers/gpu/drm/display/drm_dp_helper.c
index 8d6ce46471ae..6c91f400ecb1 100644
--- a/drivers/gpu/drm/display/drm_dp_helper.c
+++ b/drivers/gpu/drm/display/drm_dp_helper.c
@@ -2913,6 +2913,84 @@ void drm_dp_vsc_sdp_log(struct drm_printer *p, const struct drm_dp_vsc_sdp *vsc)
  }
  EXPORT_SYMBOL(drm_dp_vsc_sdp_log);

+/**
+ * drm_dp_vsc_sdp_pack() - pack a given vsc sdp into generic dp_sdp
+ * @vsc: vsc sdp initialized according to its purpose as defined in
+ *       table 2-118 - table 2-120 in DP 1.4a specification
+ * @sdp: valid handle to the generic dp_sdp which will be packed
+ * @size: valid size of the passed sdp handle
+ *
+ * Returns length of sdp on success and error code on failure
+ */
+ssize_t drm_dp_vsc_sdp_pack(const struct drm_dp_vsc_sdp *vsc,
+                           struct dp_sdp *sdp, size_t size)
+{
+       size_t length = sizeof(struct dp_sdp);
+
+       if (size < length)
+               return -ENOSPC;
+
+       memset(sdp, 0, size);
+
+       /*
+        * Prepare VSC Header for SU as per DP 1.4a spec, Table 2-119
+        * VSC SDP Header Bytes
+        */
+       sdp->sdp_header.HB0 = 0; /* Secondary-Data Packet ID = 0 */
+       sdp->sdp_header.HB1 = vsc->sdp_type; /* Secondary-data Packet Type */
+       sdp->sdp_header.HB2 = vsc->revision; /* Revision Number */
+       sdp->sdp_header.HB3 = vsc->length; /* Number of Valid Data Bytes */
+
+       if (vsc->revision == 0x6) {
+               sdp->db[0] = 1;
+               sdp->db[3] = 1;
+       }
+
+       /*
+        * Revision 0x5 and revision 0x7 supports Pixel Encoding/Colorimetry
+        * Format as per DP 1.4a spec and DP 2.0 respectively.
+        */
+       if (!(vsc->revision == 0x5 || vsc->revision == 0x7))
+               goto out;
+
+       /* VSC SDP Payload for DB16 through DB18 */
+       /* Pixel Encoding and Colorimetry Formats  */
+       sdp->db[16] = (vsc->pixelformat & 0xf) << 4; /* DB16[7:4] */
+       sdp->db[16] |= vsc->colorimetry & 0xf; /* DB16[3:0] */
+
+       switch (vsc->bpc) {
+       case 6:
+               /* 6bpc: 0x0 */
+               break;
+       case 8:
+               sdp->db[17] = 0x1; /* DB17[3:0] */
+               break;
+       case 10:
+               sdp->db[17] = 0x2;
+               break;
+       case 12:
+               sdp->db[17] = 0x3;
+               break;
+       case 16:
+               sdp->db[17] = 0x4;
+               break;
+       default:
+               WARN(1, "Missing case %d\n", vsc->bpc);
+               return -EINVAL;
+       }
+
+       /* Dynamic Range and Component Bit Depth */
+       if (vsc->dynamic_range == DP_DYNAMIC_RANGE_CTA)
+               sdp->db[17] |= 0x80;  /* DB17[7] */
+
+       /* Content Type */
+       sdp->db[18] = vsc->content_type & 0x7;
+
+out:
+       return length;
+}
+EXPORT_SYMBOL(drm_dp_vsc_sdp_pack);
+
  /**
   * drm_dp_get_pcon_max_frl_bw() - maximum frl supported by PCON
   * @dpcd: DisplayPort configuration data
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 217196196e50..a9458df475e2 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -4089,73 +4089,6 @@ intel_dp_needs_vsc_sdp(const struct intel_crtc_state *crtc_state,
         return false;
  }

-static ssize_t intel_dp_vsc_sdp_pack(const struct drm_dp_vsc_sdp *vsc,
-                                    struct dp_sdp *sdp, size_t size)
-{
-       size_t length = sizeof(struct dp_sdp);
-
-       if (size < length)
-               return -ENOSPC;
-
-       memset(sdp, 0, size);
-
-       /*
-        * Prepare VSC Header for SU as per DP 1.4a spec, Table 2-119
-        * VSC SDP Header Bytes
-        */
-       sdp->sdp_header.HB0 = 0; /* Secondary-Data Packet ID = 0 */
-       sdp->sdp_header.HB1 = vsc->sdp_type; /* Secondary-data Packet Type */
-       sdp->sdp_header.HB2 = vsc->revision; /* Revision Number */
-       sdp->sdp_header.HB3 = vsc->length; /* Number of Valid Data Bytes */
-
-       if (vsc->revision == 0x6) {
-               sdp->db[0] = 1;
-               sdp->db[3] = 1;
-       }
-
-       /*
-        * Revision 0x5 and revision 0x7 supports Pixel Encoding/Colorimetry
-        * Format as per DP 1.4a spec and DP 2.0 respectively.
-        */
-       if (!(vsc->revision == 0x5 || vsc->revision == 0x7))
-               goto out;
-
-       /* VSC SDP Payload for DB16 through DB18 */
-       /* Pixel Encoding and Colorimetry Formats  */
-       sdp->db[16] = (vsc->pixelformat & 0xf) << 4; /* DB16[7:4] */
-       sdp->db[16] |= vsc->colorimetry & 0xf; /* DB16[3:0] */
-
-       switch (vsc->bpc) {
-       case 6:
-               /* 6bpc: 0x0 */
-               break;
-       case 8:
-               sdp->db[17] = 0x1; /* DB17[3:0] */
-               break;
-       case 10:
-               sdp->db[17] = 0x2;
-               break;
-       case 12:
-               sdp->db[17] = 0x3;
-               break;
-       case 16:
-               sdp->db[17] = 0x4;
-               break;
-       default:
-               MISSING_CASE(vsc->bpc);
-               break;
-       }
-       /* Dynamic Range and Component Bit Depth */
-       if (vsc->dynamic_range == DP_DYNAMIC_RANGE_CTA)
-               sdp->db[17] |= 0x80;  /* DB17[7] */
-
-       /* Content Type */
-       sdp->db[18] = vsc->content_type & 0x7;
-
-out:
-       return length;
-}
-
  static ssize_t
  intel_dp_hdr_metadata_infoframe_sdp_pack(struct drm_i915_private *i915,
                                          const struct hdmi_drm_infoframe *drm_infoframe,
@@ -4248,8 +4181,8 @@ static void intel_write_dp_sdp(struct intel_encoder *encoder,

         switch (type) {
         case DP_SDP_VSC:
-               len = intel_dp_vsc_sdp_pack(&crtc_state->infoframes.vsc, &sdp,
-                                           sizeof(sdp));
+               len = drm_dp_vsc_sdp_pack(&crtc_state->infoframes.vsc, &sdp,
+                                         sizeof(sdp));
                 break;
         case HDMI_PACKET_TYPE_GAMUT_METADATA:
                 len = intel_dp_hdr_metadata_infoframe_sdp_pack(dev_priv,
diff --git a/include/drm/display/drm_dp_helper.h b/include/drm/display/drm_dp_helper.h
index d02014a87f12..8474504d4c88 100644
--- a/include/drm/display/drm_dp_helper.h
+++ b/include/drm/display/drm_dp_helper.h
@@ -812,4 +812,7 @@ int drm_dp_bw_overhead(int lane_count, int hactive,
                        int bpp_x16, unsigned long flags);
  int drm_dp_bw_channel_coding_efficiency(bool is_uhbr);

+ssize_t drm_dp_vsc_sdp_pack(const struct drm_dp_vsc_sdp *vsc,
+                           struct dp_sdp *sdp, size_t size);
+
  #endif /* _DRM_DP_HELPER_H_ */
--
2.34.1









