[PATCH] mtd: rawnand: lpx32xx: Fix dma_request_chan() error checks

[PATCH] mtd: rawnand: lpx32xx: Fix dma_request_chan() error checks

[Piotr Wojtaszczyk]

The dma_request_chan() returns error pointer in case of error, while
dma_request_channel() returns NULL in case of error therefore different
error checks are needed for the two.

Fixes: 7326d3fb1ee3 ("mtd: rawnand: lpx32xx: Request DMA channels
using DT entries")
Signed-off-by: Piotr Wojtaszczyk <piotr.wojtaszczyk@timesys.com>
---
 drivers/mtd/nand/raw/lpc32xx_mlc.c | 2 +-
 drivers/mtd/nand/raw/lpc32xx_slc.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/nand/raw/lpc32xx_mlc.c b/drivers/mtd/nand/raw/lpc32xx_mlc.c
index 92cebe871bb4..b9c3adc54c01 100644
--- a/drivers/mtd/nand/raw/lpc32xx_mlc.c
+++ b/drivers/mtd/nand/raw/lpc32xx_mlc.c
@@ -575,7 +575,7 @@ static int lpc32xx_dma_setup(struct lpc32xx_nand_host *host)
 	dma_cap_mask_t mask;
 
 	host->dma_chan = dma_request_chan(mtd->dev.parent, "rx-tx");
-	if (!host->dma_chan) {
+	if (IS_ERR(host->dma_chan)) {
 		/* fallback to request using platform data */
 		if (!host->pdata || !host->pdata->dma_filter) {
 			dev_err(mtd->dev.parent, "no DMA platform data\n");
diff --git a/drivers/mtd/nand/raw/lpc32xx_slc.c b/drivers/mtd/nand/raw/lpc32xx_slc.c
index 3b7e3d259785..ade971e4cc3b 100644
--- a/drivers/mtd/nand/raw/lpc32xx_slc.c
+++ b/drivers/mtd/nand/raw/lpc32xx_slc.c
@@ -722,7 +722,7 @@ static int lpc32xx_nand_dma_setup(struct lpc32xx_nand_host *host)
 	dma_cap_mask_t mask;
 
 	host->dma_chan = dma_request_chan(mtd->dev.parent, "rx-tx");
-	if (!host->dma_chan) {
+	if (IS_ERR(host->dma_chan)) {
 		/* fallback to request using platform data */
 		if (!host->pdata || !host->pdata->dma_filter) {
 			dev_err(mtd->dev.parent, "no DMA platform data\n");
-- 
2.25.1

Re: [PATCH] mtd: rawnand: lpx32xx: Fix dma_request_chan() error checks

[Miquel Raynal]

Hi Piotr,

piotr.wojtaszczyk@timesys.com wrote on Fri,  5 Jul 2024 11:38:47 +0200:

> The dma_request_chan() returns error pointer in case of error, while
> dma_request_channel() returns NULL in case of error therefore different
> error checks are needed for the two.
> 
> Fixes: 7326d3fb1ee3 ("mtd: rawnand: lpx32xx: Request DMA channels
> using DT entries")

Pleae don't split the commit title over two lines.

Missing: Cc: stable.

> Signed-off-by: Piotr Wojtaszczyk <piotr.wojtaszczyk@timesys.com>

Thanks,
Miquèl

Re: [PATCH] mtd: rawnand: lpx32xx: Fix dma_request_chan() error checks

[Markus Elfring]

…
> dma_request_channel() returns NULL in case of error …

* I find this information not relevant here because such a function
  is not called at the affected source code places.

* Please improve such a change description with imperative wordings.
  https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v6.10-rc6#n94


> Fixes: 7326d3fb1ee3 ("mtd: rawnand: lpx32xx: Request DMA channels
> using DT entries")

Please omit a line break from the tag summary.
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v6.10-rc6#n145

Regards,
Markus