Re: [Intel-gfx] [RFC v1 2/6] drm/displayid: add separate drm_displayid.c

On Tue, Mar 09, 2021 at 03:54:10PM +0200, Jani Nikula wrote:

We'll be adding more DisplayID specific functions going forward, so start off by splitting out a few functions to a separate file.

We don't bother with exporting the functions; at least for now they should be needed solely within drm.ko.

No functional changes.

Signed-off-by: Jani Nikula jani.nikula@intel.com

Reviewed-by: Ville Syrjälä ville.syrjala@linux.intel.com

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drivers/gpu/drm/Makefile | 2 +- drivers/gpu/drm/drm_displayid.c | 59 +++++++++++++++++++++++++++++++++ drivers/gpu/drm/drm_edid.c | 58 ++------------------------------ include/drm/drm_displayid.h | 8 +++++ include/drm/drm_edid.h | 3 ++ 5 files changed, 73 insertions(+), 57 deletions(-) create mode 100644 drivers/gpu/drm/drm_displayid.c

diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile index 5eb5bf7c16e3..78ef2fd14f10 100644 --- a/drivers/gpu/drm/Makefile +++ b/drivers/gpu/drm/Makefile @@ -7,7 +7,7 @@ drm-y := drm_auth.o drm_cache.o \ drm_file.o drm_gem.o drm_ioctl.o drm_irq.o \ drm_drv.o \ drm_sysfs.o drm_hashtab.o drm_mm.o \

• drm_crtc.o drm_fourcc.o drm_modes.o drm_edid.o \
  

• drm_crtc.o drm_fourcc.o drm_modes.o drm_edid.o drm_displayid.o \
  

  drm_encoder_slave.o \ drm_trace_points.o drm_prime.o \ drm_rect.o drm_vma_manager.o drm_flip_work.o \

diff --git a/drivers/gpu/drm/drm_displayid.c b/drivers/gpu/drm/drm_displayid.c new file mode 100644 index 000000000000..908bbe6feb61 --- /dev/null +++ b/drivers/gpu/drm/drm_displayid.c @@ -0,0 +1,59 @@ +// SPDX-License-Identifier: MIT +/*

• • Copyright © 2021 Intel Corporation
• */

+#include <drm/drm_displayid.h> +#include <drm/drm_edid.h> +#include <drm/drm_print.h>

+static int validate_displayid(const u8 *displayid, int length, int idx) +{

• int i, dispid_length;
• u8 csum = 0;
• const struct displayid_hdr *base;
• base = (const struct displayid_hdr *)&displayid[idx];
• DRM_DEBUG_KMS("base revision 0x%x, length %d, %d %d\n",

•       base->rev, base->bytes, base->prod_id, base->ext_count);
  

• /* +1 for DispID checksum */
• dispid_length = sizeof(*base) + base->bytes + 1;
• if (dispid_length > length - idx)

• return -EINVAL;
  

• for (i = 0; i < dispid_length; i++)

• csum += displayid[idx + i];
  

• if (csum) {

• DRM_NOTE("DisplayID checksum invalid, remainder is %d\n", csum);
  

• return -EINVAL;
  

• }
• return 0;

+}

+const u8 *drm_find_displayid_extension(const struct edid *edid,

• 		       int *length, int *idx,
  

• 		       int *ext_index)
  

+{

• const u8 *displayid = drm_find_edid_extension(edid, DISPLAYID_EXT, ext_index);
• const struct displayid_hdr *base;
• int ret;
• if (!displayid)

• return NULL;
  

• /* EDID extensions block checksum isn't for us */
• *length = EDID_LENGTH - 1;
• *idx = 1;
• ret = validate_displayid(displayid, *length, *idx);
• if (ret)

• return NULL;
  

• base = (const struct displayid_hdr *)&displayid[*idx];
• *length = *idx + sizeof(*base) + base->bytes;
• return displayid;

+} diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index d510b827a1f8..58e61f792bc7 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -1585,8 +1585,6 @@ module_param_named(edid_fixup, edid_fixup, int, 0400); MODULE_PARM_DESC(edid_fixup, "Minimum number of valid EDID header bytes (0-8, default 6)");

-static int validate_displayid(const u8 *displayid, int length, int idx);

static int drm_edid_block_checksum(const u8 *raw_edid) { int i; @@ -3241,8 +3239,8 @@ add_detailed_modes(struct drm_connector *connector, struct edid *edid, /*

• Search EDID for CEA extension block.

*/ -static const u8 *drm_find_edid_extension(const struct edid *edid,

• 			 int ext_id, int *ext_index)
  

+const u8 *drm_find_edid_extension(const struct edid *edid,

• 		  int ext_id, int *ext_index)
  

{ const u8 *edid_ext = NULL; int i; @@ -3266,32 +3264,6 @@ static const u8 *drm_find_edid_extension(const struct edid *edid, return edid_ext; }

-static const u8 *drm_find_displayid_extension(const struct edid *edid,

• 			      int *length, int *idx,
  

• 			      int *ext_index)
  

-{

• const u8 *displayid = drm_find_edid_extension(edid, DISPLAYID_EXT, ext_index);
• const struct displayid_hdr *base;
• int ret;
• if (!displayid)

• return NULL;
  

• /* EDID extensions block checksum isn't for us */
• *length = EDID_LENGTH - 1;
• *idx = 1;
• ret = validate_displayid(displayid, *length, *idx);
• if (ret)

• return NULL;
  

• base = (const struct displayid_hdr *)&displayid[*idx];
• *length = *idx + sizeof(*base) + base->bytes;
• return displayid;

-}

static const u8 *drm_find_cea_extension(const struct edid *edid) { int length, idx; @@ -5287,32 +5259,6 @@ u32 drm_add_display_info(struct drm_connector *connector, const struct edid *edi return quirks; }

-static int validate_displayid(const u8 *displayid, int length, int idx) -{

• int i, dispid_length;
• u8 csum = 0;
• const struct displayid_hdr *base;
• base = (const struct displayid_hdr *)&displayid[idx];
• DRM_DEBUG_KMS("base revision 0x%x, length %d, %d %d\n",

•       base->rev, base->bytes, base->prod_id, base->ext_count);
  

• /* +1 for DispID checksum */
• dispid_length = sizeof(*base) + base->bytes + 1;
• if (dispid_length > length - idx)

• return -EINVAL;
  

• for (i = 0; i < dispid_length; i++)

• csum += displayid[idx + i];
  

• if (csum) {

• DRM_NOTE("DisplayID checksum invalid, remainder is %d\n", csum);
  

• return -EINVAL;
  

• }
• return 0;

-}

static struct drm_display_mode *drm_mode_displayid_detailed(struct drm_device *dev, struct displayid_detailed_timings_1 *timings) { diff --git a/include/drm/drm_displayid.h b/include/drm/drm_displayid.h index f141c0eff083..3c6db22a518a 100644 --- a/include/drm/drm_displayid.h +++ b/include/drm/drm_displayid.h @@ -22,6 +22,10 @@ #ifndef DRM_DISPLAYID_H #define DRM_DISPLAYID_H

+#include <linux/types.h>

+struct edid;

#define DATA_BLOCK_PRODUCT_ID 0x00 #define DATA_BLOCK_DISPLAY_PARAMETERS 0x01 #define DATA_BLOCK_COLOR_CHARACTERISTICS 0x02 @@ -100,4 +104,8 @@ struct displayid_detailed_timing_block { (idx) += sizeof(struct displayid_block) + (block)->num_bytes, \ (block) = (const struct displayid_block *)&(displayid)[idx])

+const u8 *drm_find_displayid_extension(const struct edid *edid,

• 		       int *length, int *idx,
  

• 		       int *ext_index);
  

#endif diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h index a158f585f658..759328a5eeb2 100644 --- a/include/drm/drm_edid.h +++ b/include/drm/drm_edid.h @@ -543,5 +543,8 @@ struct drm_display_mode *drm_mode_find_dmt(struct drm_device *dev, struct drm_display_mode * drm_display_mode_from_cea_vic(struct drm_device *dev, u8 video_code); +const u8 *drm_find_edid_extension(const struct edid *edid,

• 		  int ext_id, int *ext_index);
  

#endif /* __DRM_EDID_H__ */

2.20.1

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