Re: [PATCH 03/12] i2c: qup: remove redundant variables for BAM SG count

From: Christ, Austin
Date: Tue Feb 27 2018 - 16:51:22 EST


I agree with Sricharan's comments about naming, otherwise looks good.

Tested on Centriq 2400

Reviewed-by: Austin Christ <austinwc@xxxxxxxxxxxxxx>

On 2/3/2018 12:58 AM, Abhishek Sahu wrote:
The rx_nents and tx_nents are redundant. rx_buf and tx_buf can
be used for total number of SG entries.

Signed-off-by: Abhishek Sahu <absahu@xxxxxxxxxxxxxx>
---
drivers/i2c/busses/i2c-qup.c | 26 ++++++++++----------------
1 file changed, 10 insertions(+), 16 deletions(-)

diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c
index c68f433..bb83a2967 100644
--- a/drivers/i2c/busses/i2c-qup.c
+++ b/drivers/i2c/busses/i2c-qup.c
@@ -692,7 +692,7 @@ 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 len, blocks, rem;
u32 i, tlen, tx_len, tx_buf = 0, rx_buf = 0, off = 0;
u8 *tags;
@@ -707,9 +707,6 @@ 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];
@@ -748,8 +745,6 @@ static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg,
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];
@@ -775,7 +770,7 @@ 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_buf) {
qup->btx.tag.start[0] =
QUP_BAM_INPUT_EOT;
len++;
@@ -787,14 +782,13 @@ static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg,
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_buf,
DMA_MEM_TO_DEV,
DMA_PREP_INTERRUPT | DMA_PREP_FENCE);
if (!txd) {
@@ -803,7 +797,7 @@ static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg,
goto desc_err;
}
- if (!rx_nents) {
+ if (!rx_buf) {
txd->callback = qup_i2c_bam_cb;
txd->callback_param = qup;
}
@@ -816,9 +810,9 @@ 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_buf) {
rxd = dmaengine_prep_slave_sg(qup->brx.dma, qup->brx.sg,
- rx_nents, DMA_DEV_TO_MEM,
+ rx_buf, DMA_DEV_TO_MEM,
DMA_PREP_INTERRUPT);
if (!rxd) {
dev_err(qup->dev, "failed to get rx desc\n");
@@ -853,7 +847,7 @@ static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg,
goto desc_err;
}
- if (rx_nents)
+ if (rx_buf)
writel(QUP_BAM_INPUT_EOT,
qup->base + QUP_OUT_FIFO_BASE);
@@ -871,10 +865,10 @@ 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_buf, DMA_TO_DEVICE);
- if (rx_nents)
- dma_unmap_sg(qup->dev, qup->brx.sg, rx_nents,
+ if (rx_buf)
+ dma_unmap_sg(qup->dev, qup->brx.sg, rx_buf,
DMA_FROM_DEVICE);
return ret;


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