ata: libata: Improve return value of atapi_check_dma()

atapi_check_dma() allows a LLD to filter ATAPI commands, returning a
status indicating whether or not it is OK to use DMA for the supplied
ATAPI command.

Change atapi_check_dma() to return -EOPNOTSUPP instead of 1 for an
ATAPI command that is not allowed to use DMA.

Signed-off-by: Huacai Chen <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[cassel: improve commit log]
Signed-off-by: Niklas Cassel <[email protected]>

Author: chenhuacai

drivers/ata/libata-core.c

@@ -4579,7 +4579,7 @@ int atapi_check_dma(struct ata_queued_cmd *qc)
 	 */
 	if (!(qc->dev->quirks & ATA_QUIRK_ATAPI_MOD16_DMA) &&
 	    unlikely(qc->nbytes & 15))
-		return 1;
+		return -EOPNOTSUPP;
 
 	if (ap->ops->check_atapi_dma)
 		return ap->ops->check_atapi_dma(qc);