[PATCH v2 04/13] i2c: qup: remove redundant variables for BAM SG count

From: Abhishek Sahu
Date: Mon Mar 12 2018 - 09:17:58 EST


The rx_nents and tx_nents are redundant. rx_buf and tx_buf can
be used for total number of SG entries. Since rx_buf and tx_buf
give the impression that it is buffer instead of count so rename
it to tx_cnt and rx_cnt for giving it more meaningful variable
name.

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

* Changes from v1:

1. Changed rx_buf/tx_buf to tx_cnt/rx_cnt
2. Modified commit message for the same

drivers/i2c/busses/i2c-qup.c | 42 ++++++++++++++++++------------------------
1 file changed, 18 insertions(+), 24 deletions(-)

diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c
index f6ea074..d970458 100644
--- a/drivers/i2c/busses/i2c-qup.c
+++ b/drivers/i2c/busses/i2c-qup.c
@@ -683,8 +683,8 @@ static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg,
struct dma_async_tx_descriptor *txd, *rxd = NULL;
int ret = 0, idx = 0, limit = QUP_READ_LIMIT;
dma_cookie_t cookie_rx, cookie_tx;
- u32 rx_nents = 0, tx_nents = 0, len, blocks, rem;
- u32 i, tlen, tx_len, tx_buf = 0, rx_buf = 0, off = 0;
+ u32 len, blocks, rem;
+ u32 i, tlen, tx_len, tx_cnt = 0, rx_cnt = 0, off = 0;
u8 *tags;

while (idx < num) {
@@ -698,9 +698,6 @@ static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg,
rem = msg->len - (blocks - 1) * limit;

if (msg->flags & I2C_M_RD) {
- rx_nents += (blocks * 2) + 1;
- tx_nents += 1;
-
while (qup->blk.pos < blocks) {
tlen = (i == (blocks - 1)) ? rem : limit;
tags = &qup->start_tag.start[off + len];
@@ -708,14 +705,14 @@ static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg,
qup->blk.data_len -= tlen;

/* scratch buf to read the start and len tags */
- ret = qup_sg_set_buf(&qup->brx.sg[rx_buf++],
+ ret = qup_sg_set_buf(&qup->brx.sg[rx_cnt++],
&qup->brx.tag.start[0],
2, qup, DMA_FROM_DEVICE);

if (ret)
return ret;

- ret = qup_sg_set_buf(&qup->brx.sg[rx_buf++],
+ ret = qup_sg_set_buf(&qup->brx.sg[rx_cnt++],
&msg->buf[limit * i],
tlen, qup,
DMA_FROM_DEVICE);
@@ -725,7 +722,7 @@ static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg,
i++;
qup->blk.pos = i;
}
- ret = qup_sg_set_buf(&qup->btx.sg[tx_buf++],
+ ret = qup_sg_set_buf(&qup->btx.sg[tx_cnt++],
&qup->start_tag.start[off],
len, qup, DMA_TO_DEVICE);
if (ret)
@@ -733,28 +730,26 @@ static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg,

off += len;
/* scratch buf to read the BAM EOT and FLUSH tags */
- ret = qup_sg_set_buf(&qup->brx.sg[rx_buf++],
+ ret = qup_sg_set_buf(&qup->brx.sg[rx_cnt++],
&qup->brx.tag.start[0],
2, qup, DMA_FROM_DEVICE);
if (ret)
return ret;
} else {
- tx_nents += (blocks * 2);
-
while (qup->blk.pos < blocks) {
tlen = (i == (blocks - 1)) ? rem : limit;
tags = &qup->start_tag.start[off + tx_len];
len = qup_i2c_set_tags(tags, qup, msg, 1);
qup->blk.data_len -= tlen;

- ret = qup_sg_set_buf(&qup->btx.sg[tx_buf++],
+ ret = qup_sg_set_buf(&qup->btx.sg[tx_cnt++],
tags, len,
qup, DMA_TO_DEVICE);
if (ret)
return ret;

tx_len += len;
- ret = qup_sg_set_buf(&qup->btx.sg[tx_buf++],
+ ret = qup_sg_set_buf(&qup->btx.sg[tx_cnt++],
&msg->buf[limit * i],
tlen, qup, DMA_TO_DEVICE);
if (ret)
@@ -766,26 +761,25 @@ static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg,

if (idx == (num - 1)) {
len = 1;
- if (rx_nents) {
+ if (rx_cnt) {
qup->btx.tag.start[0] =
QUP_BAM_INPUT_EOT;
len++;
}
qup->btx.tag.start[len - 1] =
QUP_BAM_FLUSH_STOP;
- ret = qup_sg_set_buf(&qup->btx.sg[tx_buf++],
+ ret = qup_sg_set_buf(&qup->btx.sg[tx_cnt++],
&qup->btx.tag.start[0],
len, qup, DMA_TO_DEVICE);
if (ret)
return ret;
- tx_nents += 1;
}
}
idx++;
msg++;
}

- txd = dmaengine_prep_slave_sg(qup->btx.dma, qup->btx.sg, tx_nents,
+ txd = dmaengine_prep_slave_sg(qup->btx.dma, qup->btx.sg, tx_cnt,
DMA_MEM_TO_DEV,
DMA_PREP_INTERRUPT | DMA_PREP_FENCE);
if (!txd) {
@@ -794,7 +788,7 @@ static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg,
goto desc_err;
}

- if (!rx_nents) {
+ if (!rx_cnt) {
txd->callback = qup_i2c_bam_cb;
txd->callback_param = qup;
}
@@ -807,9 +801,9 @@ static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg,

dma_async_issue_pending(qup->btx.dma);

- if (rx_nents) {
+ if (rx_cnt) {
rxd = dmaengine_prep_slave_sg(qup->brx.dma, qup->brx.sg,
- rx_nents, DMA_DEV_TO_MEM,
+ rx_cnt, DMA_DEV_TO_MEM,
DMA_PREP_INTERRUPT);
if (!rxd) {
dev_err(qup->dev, "failed to get rx desc\n");
@@ -844,7 +838,7 @@ static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg,
goto desc_err;
}

- if (rx_nents)
+ if (rx_cnt)
writel(QUP_BAM_INPUT_EOT,
qup->base + QUP_OUT_FIFO_BASE);

@@ -862,10 +856,10 @@ static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg,
}

desc_err:
- dma_unmap_sg(qup->dev, qup->btx.sg, tx_nents, DMA_TO_DEVICE);
+ dma_unmap_sg(qup->dev, qup->btx.sg, tx_cnt, DMA_TO_DEVICE);

- if (rx_nents)
- dma_unmap_sg(qup->dev, qup->brx.sg, rx_nents,
+ if (rx_cnt)
+ dma_unmap_sg(qup->dev, qup->brx.sg, rx_cnt,
DMA_FROM_DEVICE);

return ret;
--
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