[PATCH v2 03/13] i2c: qup: minor code reorganization for use_dma

From: Abhishek Sahu
Date: Mon Mar 12 2018 - 09:18:20 EST


1. Assigns use_dma in qup_dev structure itself which will
help in subsequent patches to determine the mode in IRQ handler.
2. Does minor code reorganization for loops to reduce the
unnecessary comparison and assignment.

Signed-off-by: Abhishek Sahu <absahu@xxxxxxxxxxxxxx>
Reviewed-by: Austin Christ <austinwc@xxxxxxxxxxxxxx>
Reviewed-by: Andy Gross <andy.gross@xxxxxxxxxx>
---

* Changes from v1: None

drivers/i2c/busses/i2c-qup.c | 19 +++++++++++--------
1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c
index 75e9819..f6ea074 100644
--- a/drivers/i2c/busses/i2c-qup.c
+++ b/drivers/i2c/busses/i2c-qup.c
@@ -181,6 +181,8 @@ struct qup_i2c_dev {

/* dma parameters */
bool is_dma;
+ /* To check if the current transfer is using DMA */
+ bool use_dma;
struct dma_pool *dpool;
struct qup_i2c_tag start_tag;
struct qup_i2c_bam brx;
@@ -1288,7 +1290,7 @@ 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, use_dma = 0;
+ int ret, len, idx = 0;

qup->bus_err = 0;
qup->qup_err = 0;
@@ -1317,13 +1319,12 @@ static int qup_i2c_xfer_v2(struct i2c_adapter *adap,
len = (msgs[idx].len > qup->out_fifo_sz) ||
(msgs[idx].len > qup->in_fifo_sz);

- if ((!is_vmalloc_addr(msgs[idx].buf)) && len) {
- use_dma = 1;
- } else {
- use_dma = 0;
+ if (is_vmalloc_addr(msgs[idx].buf) || !len)
break;
- }
}
+
+ if (idx == num)
+ qup->use_dma = true;
}

idx = 0;
@@ -1347,15 +1348,17 @@ static int qup_i2c_xfer_v2(struct i2c_adapter *adap,

reinit_completion(&qup->xfer);

- if (use_dma) {
+ if (qup->use_dma) {
ret = qup_i2c_bam_xfer(adap, &msgs[idx], num);
+ qup->use_dma = false;
+ break;
} else {
if (msgs[idx].flags & I2C_M_RD)
ret = qup_i2c_read_one_v2(qup, &msgs[idx]);
else
ret = qup_i2c_write_one_v2(qup, &msgs[idx]);
}
- } while ((idx++ < (num - 1)) && !use_dma && !ret);
+ } while ((idx++ < (num - 1)) && !ret);

if (!ret)
ret = qup_i2c_change_state(qup, QUP_RESET_STATE);
--
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