From: Mats Randgaard <matrandg@xxxxxxxxx>
i2c_wr() is called from ops and the interrupt service routine, while
state->wr_data is shared and unprotected, and could be overwritten.
This shared buffer is therefore replaced with a local array with fixed
size. The array has the size of one EDID block (128 bytes) + 2 bytes
i2c address, and the EDID is written block by block (up to 8 blocks).
Signed-off-by: Mats Randgaard <matrandg@xxxxxxxxx>
---
drivers/media/i2c/tc358743.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/drivers/media/i2c/tc358743.c b/drivers/media/i2c/tc358743.c
index 77b8011..cc38896 100644
--- a/drivers/media/i2c/tc358743.c
+++ b/drivers/media/i2c/tc358743.c
@@ -59,8 +59,7 @@ MODULE_LICENSE("GPL");
#define EDID_NUM_BLOCKS_MAX 8
#define EDID_BLOCK_SIZE 128
-/* Max transfer size done by I2C transfer functions */
-#define MAX_XFER_SIZE (EDID_NUM_BLOCKS_MAX * EDID_BLOCK_SIZE + 2)
+#define I2C_MAX_XFER_SIZE (EDID_BLOCK_SIZE + 2)
static const struct v4l2_dv_timings_cap tc358743_timings_cap = {
.type = V4L2_DV_BT_656_1120,
@@ -97,9 +96,6 @@ struct tc358743_state {
/* edid */
u8 edid_blocks_written;
- /* used by i2c_wr() */
- u8 wr_data[MAX_XFER_SIZE];
-
struct v4l2_dv_timings timings;
u32 mbus_fmt_code;
@@ -149,13 +145,15 @@ static void i2c_wr(struct v4l2_subdev *sd, u16 reg, u8 *values, u32 n)
{
struct tc358743_state *state = to_state(sd);
struct i2c_client *client = state->i2c_client;
- u8 *data = state->wr_data;
int err, i;
struct i2c_msg msg;
+ u8 data[I2C_MAX_XFER_SIZE];
- if ((2 + n) > sizeof(state->wr_data))
+ if ((2 + n) > I2C_MAX_XFER_SIZE) {
+ n = I2C_MAX_XFER_SIZE - 2;
v4l2_warn(sd, "i2c wr reg=%04x: len=%d is too big!\n",
reg, 2 + n);
+ }
msg.addr = client->addr;
msg.buf = data;
@@ -1581,6 +1579,7 @@ static int tc358743_s_edid(struct v4l2_subdev *sd,
{
struct tc358743_state *state = to_state(sd);
u16 edid_len = edid->blocks * EDID_BLOCK_SIZE;
+ int i;
v4l2_dbg(2, debug, sd, "%s, pad %d, start block %d, blocks %d\n",
__func__, edid->pad, edid->start_block, edid->blocks);
@@ -1606,7 +1605,8 @@ static int tc358743_s_edid(struct v4l2_subdev *sd,
return 0;
}
- i2c_wr(sd, EDID_RAM, edid->edid, edid_len);
+ for (i = 0; i < edid_len; i += EDID_BLOCK_SIZE)
+ i2c_wr(sd, EDID_RAM + i, edid->edid + i, EDID_BLOCK_SIZE);
state->edid_blocks_written = edid->blocks;
--
2.5.0
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