2016-03-31 03:13:29

by Shawn Lin

Subject: [PATCH v2] spi: rockchip: fix warning of static check

Use dma_request_chan instead of dma_request_slave_channel,
in this case we can check EPROBE_DEFER without static
warning.

Reported-by: Dan Carpenter <[email protected]>
Cc: Doug Anderson <[email protected]>
Cc: Dan Carpenter <[email protected]>
Signed-off-by: Shawn Lin <[email protected]>

---

Changes in v2:
- use dma_request_chan and replace IS_ERR_OR_NULL()
with IS_ERR
- do the same for rx

drivers/spi/spi-rockchip.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c
index b71c1ae..6c6c001 100644
--- a/drivers/spi/spi-rockchip.c
+++ b/drivers/spi/spi-rockchip.c
@@ -730,23 +730,27 @@ static int rockchip_spi_probe(struct platform_device *pdev)
master->transfer_one = rockchip_spi_transfer_one;
master->handle_err = rockchip_spi_handle_err;

- rs->dma_tx.ch = dma_request_slave_channel(rs->dev, "tx");
- if (IS_ERR_OR_NULL(rs->dma_tx.ch)) {
+ rs->dma_tx.ch = dma_request_chan(rs->dev, "tx");
+ if (IS_ERR(rs->dma_tx.ch)) {
/* Check tx to see if we need defer probing driver */
if (PTR_ERR(rs->dma_tx.ch) == -EPROBE_DEFER) {
ret = -EPROBE_DEFER;
goto err_get_fifo_len;
}
dev_warn(rs->dev, "Failed to request TX DMA channel\n");
+ rs->dma_tx.ch = NULL;
}

- rs->dma_rx.ch = dma_request_slave_channel(rs->dev, "rx");
- if (!rs->dma_rx.ch) {
- if (rs->dma_tx.ch) {
+ rs->dma_rx.ch = dma_request_chan(rs->dev, "rx");
+ if (IS_ERR(rs->dma_rx.ch)) {
+ if (PTR_ERR(rs->dma_rx.ch) == -EPROBE_DEFER) {
dma_release_channel(rs->dma_tx.ch);
rs->dma_tx.ch = NULL;
+ ret = -EPROBE_DEFER;
+ goto err_get_fifo_len;
}
dev_warn(rs->dev, "Failed to request RX DMA channel\n");
+ rs->dma_rx.ch = NULL;
}

if (rs->dma_tx.ch && rs->dma_rx.ch) {
--
2.3.7

2016-03-31 17:52:13

by Doug Anderson

Subject: Re: [PATCH v2] spi: rockchip: fix warning of static check

Shawn,

On Wed, Mar 30, 2016 at 8:11 PM, Shawn Lin <[email protected]> wrote:
> Use dma_request_chan instead of dma_request_slave_channel,
> in this case we can check EPROBE_DEFER without static
> warning.

Technically this is more than just a warning fix. The previous commit
61cadcf46cfd ("spi: rockchip: check requesting dma channel with
EPROBE_DEFER") could never have done what it was supposed to do
because dma_request_slave_channel() could never return EPROBE_DEFER.
...so really this makes the previous commit work properly.


> Reported-by: Dan Carpenter <[email protected]>
> Cc: Doug Anderson <[email protected]>
> Cc: Dan Carpenter <[email protected]>
> Signed-off-by: Shawn Lin <[email protected]>
>
> ---
>
> Changes in v2:
> - use dma_request_chan and replace IS_ERR_OR_NULL()
> with IS_ERR
> - do the same for rx
>
> drivers/spi/spi-rockchip.c | 14 +++++++++-----
> 1 file changed, 9 insertions(+), 5 deletions(-)

Reviewed-by: Douglas Anderson <[email protected]>