[PATCH 4.19 297/361] media: cec: make cec_get_edid_spa_location() an inline function

Greg Kroah-Hartman
2018-11-11T22:28:37Z

From: Hans Verkuil <hans.verkuil@cisco.com>

commit b915bf575d5b7774d0f22d57d6c143e07dcaade2 upstream.

This function is needed by both V4L2 and CEC, so move this to
cec.h as a static inline since there are no obvious shared
modules between the two subsystems.

This patch, together with the following ones, fixes a
dependency bug: if CEC_CORE is disabled, then building adv7604
(and other HDMI receivers) will fail because an essential
function is now stubbed out.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Cc: <stable@vger.kernel.org> # for v4.17 and up
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/media/cec/cec-edid.c | 60 ------------------------------------
include/media/cec.h | 70 +++++++++++++++++++++++++++++++++++++++++++
2 files changed, 70 insertions(+), 60 deletions(-)

--- a/drivers/media/cec/cec-edid.c
+++ b/drivers/media/cec/cec-edid.c
@@ -10,66 +10,6 @@
#include <linux/types.h>
#include <media/cec.h>

-/*
- * This EDID is expected to be a CEA-861 compliant, which means that there are
- * at least two blocks and one or more of the extensions blocks are CEA-861
- * blocks.
- *
- * The returned location is guaranteed to be < size - 1.
- */
-static unsigned int cec_get_edid_spa_location(const u8 *edid, unsigned int size)
-{
- unsigned int blocks = size / 128;
- unsigned int block;
- u8 d;
-
- /* Sanity check: at least 2 blocks and a multiple of the block size */
- if (blocks < 2 || size % 128)
- return 0;
-
- /*
- * If there are fewer extension blocks than the size, then update
- * 'blocks'. It is allowed to have more extension blocks than the size,
- * since some hardware can only read e.g. 256 bytes of the EDID, even
- * though more blocks are present. The first CEA-861 extension block
- * should normally be in block 1 anyway.
- */
- if (edid[0x7e] + 1 < blocks)
- blocks = edid[0x7e] + 1;
-
- for (block = 1; block < blocks; block++) {
- unsigned int offset = block * 128;
-
- /* Skip any non-CEA-861 extension blocks */
- if (edid[offset] != 0x02 || edid[offset + 1] != 0x03)
- continue;
-
- /* search Vendor Specific Data Block (tag 3) */
- d = edid[offset + 2] & 0x7f;
- /* Check if there are Data Blocks */
- if (d <= 4)
- continue;
- if (d > 4) {
- unsigned int i = offset + 4;
- unsigned int end = offset + d;
-
- /* Note: 'end' is always < 'size' */
- do {
- u8 tag = edid[i] >> 5;
- u8 len = edid[i] & 0x1f;
-
- if (tag == 3 && len >= 5 && i + len <= end &&
- edid[i + 1] == 0x03 &&
- edid[i + 2] == 0x0c &&
- edid[i + 3] == 0x00)
- return i + 4;
- i += len + 1;
- } while (i < end);
- }
- }
- return 0;
-}
-
u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size,
unsigned int *offset)
{
--- a/include/media/cec.h
+++ b/include/media/cec.h
@@ -461,4 +461,74 @@ static inline void cec_phys_addr_invalid
cec_s_phys_addr(adap, CEC_PHYS_ADDR_INVALID, false);
}

+/**
+ * cec_get_edid_spa_location() - find location of the Source Physical Address
+ *
+ * @edid: the EDID
+ * @size: the size of the EDID
+ *
+ * This EDID is expected to be a CEA-861 compliant, which means that there are
+ * at least two blocks and one or more of the extensions blocks are CEA-861
+ * blocks.
+ *
+ * The returned location is guaranteed to be <= size-2.
+ *
+ * This is an inline function since it is used by both CEC and V4L2.
+ * Ideally this would go in a module shared by both, but it is overkill to do
+ * that for just a single function.
+ */
+static inline unsigned int cec_get_edid_spa_location(const u8 *edid,
+ unsigned int size)
+{
+ unsigned int blocks = size / 128;
+ unsigned int block;
+ u8 d;
+
+ /* Sanity check: at least 2 blocks and a multiple of the block size */
+ if (blocks < 2 || size % 128)
+ return 0;
+
+ /*
+ * If there are fewer extension blocks than the size, then update
+ * 'blocks'. It is allowed to have more extension blocks than the size,
+ * since some hardware can only read e.g. 256 bytes of the EDID, even
+ * though more blocks are present. The first CEA-861 extension block
+ * should normally be in block 1 anyway.
+ */
+ if (edid[0x7e] + 1 < blocks)
+ blocks = edid[0x7e] + 1;
+
+ for (block = 1; block < blocks; block++) {
+ unsigned int offset = block * 128;
+
+ /* Skip any non-CEA-861 extension blocks */
+ if (edid[offset] != 0x02 || edid[offset + 1] != 0x03)
+ continue;
+
+ /* search Vendor Specific Data Block (tag 3) */
+ d = edid[offset + 2] & 0x7f;
+ /* Check if there are Data Blocks */
+ if (d <= 4)
+ continue;
+ if (d > 4) {
+ unsigned int i = offset + 4;
+ unsigned int end = offset + d;
+
+ /* Note: 'end' is always < 'size' */
+ do {
+ u8 tag = edid[i] >> 5;
+ u8 len = edid[i] & 0x1f;
+
+ if (tag == 3 && len >= 5 && i + len <= end &&
+ edid[i + 1] == 0x03 &&
+ edid[i + 2] == 0x0c &&
+ edid[i + 3] == 0x00)
+ return i + 4;
+ i += len + 1;
+ } while (i < end);
+ }
+ }
+ return 0;
+}
+
#endif /* _MEDIA_CEC_H */