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authorAbhishek Sahu <absahu@codeaurora.org>2018-03-12 18:44:57 +0530
committerWolfram Sang <wsa@the-dreams.de>2018-03-24 13:20:09 +0100
commit08f15963bc751bc818294c0f75a9aaca299c4052 (patch)
treef3aba4bdc2c882b5716c6c5728dce79b7f9bfc3f /drivers/i2c
parent3f450d3eea14799b14192231840c1753a660f150 (diff)
downloadlinux-08f15963bc751bc818294c0f75a9aaca299c4052.tar.gz
i2c: qup: use the complete transfer length to choose DMA mode
Currently each message length in complete transfer is being
checked for determining DMA mode and if any of the message length
is less than FIFO length then non DMA mode is being used which
will increase overhead. DMA can be used for any length and it
should be determined with complete transfer length. Now, this
patch selects DMA mode if the total length is greater than FIFO
length.

Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Reviewed-by: Austin Christ <austinwc@codeaurora.org>
Reviewed-by: Andy Gross <andy.gross@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/busses/i2c-qup.c13
1 files changed, 7 insertions, 6 deletions
diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c
index d16361df1bfb..bf1b7eec8a4c 100644
--- a/drivers/i2c/busses/i2c-qup.c
+++ b/drivers/i2c/busses/i2c-qup.c
@@ -1300,7 +1300,8 @@ static int qup_i2c_xfer_v2(struct i2c_adapter *adap,
 			   int num)
 {
 	struct qup_i2c_dev *qup = i2c_get_adapdata(adap);
-	int ret, len, idx = 0;
+	int ret, idx = 0;
+	unsigned int total_len = 0;
 
 	qup->bus_err = 0;
 	qup->qup_err = 0;
@@ -1326,14 +1327,14 @@ static int qup_i2c_xfer_v2(struct i2c_adapter *adap,
 				goto out;
 			}
 
-			len = (msgs[idx].len > qup->out_fifo_sz) ||
-			      (msgs[idx].len > qup->in_fifo_sz);
-
-			if (is_vmalloc_addr(msgs[idx].buf) || !len)
+			if (is_vmalloc_addr(msgs[idx].buf))
 				break;
+
+			total_len += msgs[idx].len;
 		}
 
-		if (idx == num)
+		if (idx == num && (total_len > qup->out_fifo_sz ||
+				   total_len > qup->in_fifo_sz))
 			qup->use_dma = true;
 	}