redonkable
/
alistair23-linux
1
0
Fork 0
Code Releases Activity

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>
hifive-unleashed-5.1
Abhishek Sahu 2018-03-12 18:44:57 +05:30 committed by Wolfram Sang
parent 3f450d3eea
commit 08f15963bc
1 changed files with 7 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
drivers/i2c/busses/i2c-qup.c
View File

@ -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;
}