spi: at91-usart: Remove some dead code

Commit Message

Christophe JAILLET Sept. 17, 2023, 2:36 p.m. UTC

dma_request_chan() does not return NULL. It returns a valid pointer or an
error pointer.

So, some dead code can be removed.

The IS_ERR_OR_NULL() in the error handling path are still needed, because
the error handling path is common to the whole function and the
ctlr->dma_xx are NULL when at91_usart_spi_configure_dma() is called.

Signed-off-by: Christophe JAILLET <[e-mail]>
---
 drivers/spi/spi-at91-usart.c | 22 ++++------------------
 1 file changed, 4 insertions(+), 18 deletions(-)

Comments

Mark Brown Sept. 26, 2023, 9:22 a.m. UTC | #1

On Sun, 17 Sep 2023 16:36:26 +0200, Christophe JAILLET wrote:
> dma_request_chan() does not return NULL. It returns a valid pointer or an
> error pointer.
> 
> So, some dead code can be removed.
> 
> The IS_ERR_OR_NULL() in the error handling path are still needed, because
> the error handling path is common to the whole function and the
> ctlr->dma_xx are NULL when at91_usart_spi_configure_dma() is called.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next

Thanks!

[1/1] spi: at91-usart: Remove some dead code
      commit: 8a771075e50bef5e2a063a9f954b36a33fb7359f

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

Patch

diff --git a/drivers/spi/spi-at91-usart.c b/drivers/spi/spi-at91-usart.c
index b11d0f993cc7..1cea8e159344 100644
--- a/drivers/spi/spi-at91-usart.c
+++ b/drivers/spi/spi-at91-usart.c
@@ -132,28 +132,14 @@  static int at91_usart_spi_configure_dma(struct spi_controller *ctlr,
 	dma_cap_set(DMA_SLAVE, mask);
 
 	ctlr->dma_tx = dma_request_chan(dev, "tx");
-	if (IS_ERR_OR_NULL(ctlr->dma_tx)) {
-		if (IS_ERR(ctlr->dma_tx)) {
-			err = PTR_ERR(ctlr->dma_tx);
-			goto at91_usart_spi_error_clear;
-		}
-
-		dev_dbg(dev,
-			"DMA TX channel not available, SPI unable to use DMA\n");
-		err = -EBUSY;
+	if (IS_ERR(ctlr->dma_tx)) {
+		err = PTR_ERR(ctlr->dma_tx);
 		goto at91_usart_spi_error_clear;
 	}
 
 	ctlr->dma_rx = dma_request_chan(dev, "rx");
-	if (IS_ERR_OR_NULL(ctlr->dma_rx)) {
-		if (IS_ERR(ctlr->dma_rx)) {
-			err = PTR_ERR(ctlr->dma_rx);
-			goto at91_usart_spi_error;
-		}
-
-		dev_dbg(dev,
-			"DMA RX channel not available, SPI unable to use DMA\n");
-		err = -EBUSY;
+	if (IS_ERR(ctlr->dma_rx)) {
+		err = PTR_ERR(ctlr->dma_rx);
 		goto at91_usart_spi_error;
 	}