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 <[email protected]> Reviewed-by: Austin Christ <[email protected]> Reviewed-by: Andy Gross <[email protected]> --- * Changes from v1: 1. Removed dma_threshold from global structure 2. Modified commit message for the same drivers/i2c/busses/i2c-qup.c | 25 ++++++++++++++++--------- drivers/i2c/busses/i2c-qup.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c index d16361d..bf1b7ee 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; } -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
