diff mbox

s5k5baf: allow to handle arbitrary long i2c sequences

Message ID 1389272143-22394-1-git-send-email-a.hajda@samsung.com (mailing list archive)
State Accepted, archived
Delegated to: Sylwester Nawrocki
Headers

Commit Message

Andrzej Hajda Jan. 9, 2014, 12:55 p.m. UTC 
  Using variable length array in s5k5baf_write_arr_seq
caused an implicit assumption that i2c sequences should be short.
The patch rewrites the function so it can handle sequences
of any length and do not uses variable length array.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
---
Hi Dan and Mauro,

I hope this patch solves the issue.

Regards
Andrzej
---
 drivers/media/i2c/s5k5baf.c | 30 +++++++++++++++++++-----------
 1 file changed, 19 insertions(+), 11 deletions(-)
diff mbox

Patch

diff --git a/drivers/media/i2c/s5k5baf.c b/drivers/media/i2c/s5k5baf.c
index 089fba6..3de1287 100644
--- a/drivers/media/i2c/s5k5baf.c
+++ b/drivers/media/i2c/s5k5baf.c
@@ -478,25 +478,33 @@  static void s5k5baf_write_arr_seq(struct s5k5baf *state, u16 addr,
 				  u16 count, const u16 *seq)
 {
 	struct i2c_client *c = v4l2_get_subdevdata(&state->sd);
-	__be16 buf[count + 1];
-	int ret, n;
+	__be16 buf[65];
 
 	s5k5baf_i2c_write(state, REG_CMDWR_ADDR, addr);
 	if (state->error)
 		return;
 
+	v4l2_dbg(3, debug, c, "i2c_write_seq(count=%d): %*ph\n", count,
+		 min(2 * count, 64), seq);
+
 	buf[0] = __constant_cpu_to_be16(REG_CMD_BUF);
-	for (n = 1; n <= count; ++n)
-		buf[n] = cpu_to_be16(*seq++);
 
-	n *= 2;
-	ret = i2c_master_send(c, (char *)buf, n);
-	v4l2_dbg(3, debug, c, "i2c_write_seq(count=%d): %*ph\n", count,
-		 min(2 * count, 64), seq - count);
+	while (count > 0) {
+		int n = min_t(int, count, ARRAY_SIZE(buf) - 1);
+		int ret, i;
 
-	if (ret != n) {
-		v4l2_err(c, "i2c_write_seq: error during transfer (%d)\n", ret);
-		state->error = ret;
+		for (i = 1; i <= n; ++i)
+			buf[i] = cpu_to_be16(*seq++);
+
+		i *= 2;
+		ret = i2c_master_send(c, (char *)buf, i);
+		if (ret != i) {
+			v4l2_err(c, "i2c_write_seq: error during transfer (%d)\n", ret);
+			state->error = ret;
+			break;
+		}
+
+		count -= n;
 	}
 }