diff options
| -rw-r--r-- | drivers/gpu/drm/drm_edid.c | 152 |
1 files changed, 90 insertions, 62 deletions
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index bfa3bbb017c7..de5ca7cda7a9 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -1668,10 +1668,56 @@ bool drm_edid_are_equal(const struct edid *edid1, const struct edid *edid2) } EXPORT_SYMBOL(drm_edid_are_equal); +enum edid_block_status { + EDID_BLOCK_OK = 0, + EDID_BLOCK_NULL, + EDID_BLOCK_HEADER_CORRUPT, + EDID_BLOCK_HEADER_REPAIR, + EDID_BLOCK_HEADER_FIXED, + EDID_BLOCK_CHECKSUM, + EDID_BLOCK_VERSION, +}; + +static enum edid_block_status edid_block_check(const void *_block, + bool is_base_block) +{ + const struct edid *block = _block; + + if (!block) + return EDID_BLOCK_NULL; + + if (is_base_block) { + int score = drm_edid_header_is_valid(block); + + if (score < clamp(edid_fixup, 0, 8)) + return EDID_BLOCK_HEADER_CORRUPT; + + if (score < 8) + return EDID_BLOCK_HEADER_REPAIR; + } + + if (edid_block_compute_checksum(block) != edid_block_get_checksum(block)) + return EDID_BLOCK_CHECKSUM; + + if (is_base_block) { + if (block->version != 1) + return EDID_BLOCK_VERSION; + } + + return EDID_BLOCK_OK; +} + +static bool edid_block_status_valid(enum edid_block_status status, int tag) +{ + return status == EDID_BLOCK_OK || + status == EDID_BLOCK_HEADER_FIXED || + (status == EDID_BLOCK_CHECKSUM && tag == CEA_EXT); +} + /** * drm_edid_block_valid - Sanity check the EDID block (base or extension) * @raw_edid: pointer to raw EDID block - * @block: type of block to validate (0 for base, extension otherwise) + * @block_num: type of block to validate (0 for base, extension otherwise) * @print_bad_edid: if true, dump bad EDID blocks to the console * @edid_corrupt: if true, the header or checksum is invalid * @@ -1680,88 +1726,70 @@ EXPORT_SYMBOL(drm_edid_are_equal); * * Return: True if the block is valid, false otherwise. */ -bool drm_edid_block_valid(u8 *raw_edid, int block, bool print_bad_edid, +bool drm_edid_block_valid(u8 *_block, int block_num, bool print_bad_edid, bool *edid_corrupt) { - u8 csum; - struct edid *edid = (struct edid *)raw_edid; + struct edid *block = (struct edid *)_block; + enum edid_block_status status; + bool is_base_block = block_num == 0; + bool valid; - if (WARN_ON(!raw_edid)) + if (WARN_ON(!block)) return false; - if (edid_fixup > 8 || edid_fixup < 0) - edid_fixup = 6; - - if (block == 0) { - int score = drm_edid_header_is_valid(raw_edid); + status = edid_block_check(block, is_base_block); + if (status == EDID_BLOCK_HEADER_REPAIR) { + DRM_DEBUG("Fixing EDID header, your hardware may be failing\n"); + edid_header_fix(block); - if (score == 8) { - if (edid_corrupt) - *edid_corrupt = false; - } else if (score >= edid_fixup) { - /* Displayport Link CTS Core 1.2 rev1.1 test 4.2.2.6 - * The corrupt flag needs to be set here otherwise, the - * fix-up code here will correct the problem, the - * checksum is correct and the test fails - */ - if (edid_corrupt) - *edid_corrupt = true; - DRM_DEBUG("Fixing EDID header, your hardware may be failing\n"); - edid_header_fix(raw_edid); - } else { - if (edid_corrupt) - *edid_corrupt = true; - goto bad; - } + /* Retry with fixed header, update status if that worked. */ + status = edid_block_check(block, is_base_block); + if (status == EDID_BLOCK_OK) + status = EDID_BLOCK_HEADER_FIXED; } - csum = edid_block_compute_checksum(raw_edid); - if (csum != edid_block_get_checksum(raw_edid)) { - if (edid_corrupt) + if (edid_corrupt) { + /* + * Unknown major version isn't corrupt but we can't use it. Only + * the base block can reset edid_corrupt to false. + */ + if (is_base_block && + (status == EDID_BLOCK_OK || status == EDID_BLOCK_VERSION)) + *edid_corrupt = false; + else if (status != EDID_BLOCK_OK) *edid_corrupt = true; - - /* allow CEA to slide through, switches mangle this */ - if (edid_block_tag(raw_edid) == CEA_EXT) { - DRM_DEBUG("EDID checksum is invalid, remainder is %d\n", csum); - DRM_DEBUG("Assuming a KVM switch modified the CEA block but left the original checksum\n"); - } else { - if (print_bad_edid) - DRM_NOTE("EDID checksum is invalid, remainder is %d\n", csum); - - goto bad; - } } - /* per-block-type checks */ - switch (edid_block_tag(raw_edid)) { - case 0: /* base */ - if (edid->version != 1) { - DRM_NOTE("EDID has major version %d, instead of 1\n", edid->version); - goto bad; + /* Determine whether we can use this block with this status. */ + valid = edid_block_status_valid(status, edid_block_tag(block)); + + /* Some fairly random status printouts. */ + if (status == EDID_BLOCK_CHECKSUM) { + if (valid) { + DRM_DEBUG("EDID block checksum is invalid, remainder is %d\n", + edid_block_compute_checksum(block)); + DRM_DEBUG("Assuming a KVM switch modified the block but left the original checksum\n"); + } else if (print_bad_edid) { + DRM_NOTE("EDID block checksum is invalid, remainder is %d\n", + edid_block_compute_checksum(block)); } - - if (edid->revision > 4) - DRM_DEBUG("EDID minor > 4, assuming backward compatibility\n"); - break; - - default: - break; + } else if (status == EDID_BLOCK_VERSION) { + DRM_NOTE("EDID has major version %d, instead of 1\n", + block->version); } - return true; - -bad: - if (print_bad_edid) { - if (edid_is_zero(raw_edid, EDID_LENGTH)) { + if (!valid && print_bad_edid) { + if (edid_is_zero(block, EDID_LENGTH)) { pr_notice("EDID block is all zeroes\n"); } else { pr_notice("Raw EDID:\n"); print_hex_dump(KERN_NOTICE, " \t", DUMP_PREFIX_NONE, 16, 1, - raw_edid, EDID_LENGTH, false); + block, EDID_LENGTH, false); } } - return false; + + return valid; } EXPORT_SYMBOL(drm_edid_block_valid); |