i2c: qup: change completion timeout according to transfer length

Currently the completion timeout is being taken according to
maximum transfer length which is too high if SCL is operating in
high frequency. This patch calculates timeout on the basis of
one-byte transfer time and uses the same for completion timeout.

Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Reviewed-by: Andy Gross <andy.gross@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

1 files changed, 10 insertions, 3 deletions

diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c
index bf1b7eec8a4c..13c751e2dd9a 100644
--- a/drivers/i2c/busses/i2c-qup.c
+++ b/drivers/i2c/busses/i2c-qup.c
@@ -121,8 +121,12 @@
 #define MX_TX_RX_LEN                    SZ_64K
 #define MX_BLOCKS                       (MX_TX_RX_LEN / QUP_READ_LIMIT)
 
-/* Max timeout in ms for 32k bytes */
-#define TOUT_MAX                        300
+/*
+ * Minimum transfer timeout for i2c transfers in seconds. It will be added on
+ * the top of maximum transfer time calculated from i2c bus speed to compensate
+ * the overheads.
+ */
+#define TOUT_MIN                        2
 
 /* Default values. Use these if FW query fails */
 #define DEFAULT_CLK_FREQ 100000
@@ -163,6 +167,7 @@ struct qup_i2c_dev {
         int                     in_blk_sz;
 
         unsigned long           one_byte_t;
+        unsigned long           xfer_timeout;
         struct qup_i2c_block    blk;
 
         struct i2c_msg          *msg;
@@ -849,7 +854,7 @@ static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg,
                 dma_async_issue_pending(qup->brx.dma);
         }
 
-        if (!wait_for_completion_timeout(&qup->xfer, TOUT_MAX * HZ)) {
+        if (!wait_for_completion_timeout(&qup->xfer, qup->xfer_timeout)) {
                 dev_err(qup->dev, "normal trans timed out\n");
                 ret = -ETIMEDOUT;
         }
@@ -1605,6 +1610,8 @@ nodma:
          */
         one_bit_t = (USEC_PER_SEC / clk_freq) + 1;
         qup->one_byte_t = one_bit_t * 9;
+        qup->xfer_timeout = TOUT_MIN * HZ +
+                            usecs_to_jiffies(MX_TX_RX_LEN * qup->one_byte_t);
 
         dev_dbg(qup->dev, "IN:block:%d, fifo:%d, OUT:block:%d, fifo:%d\n",
                 qup->in_blk_sz, qup->in_fifo_sz,