5.15-stable review patch. If anyone has any objections, please let me know.

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From: Miaoqian Lin linmq006@gmail.com

commit eb4917f557d43c7a1c805dd73ffcdfddb2aba39a upstream.

Check for returned DMA addresses using specialized dma_mapping_error() helper which is generally recommended for this purpose by Documentation/core-api/dma-api.rst:

"In some circumstances dma_map_single(), ... will fail to create a mapping. A driver can check for these errors by testing the returned DMA address with dma_mapping_error()."

Found via static analysis and this is similar to commit fa0308134d26 ("ALSA: memalloc: prefer dma_mapping_error() over explicit address checking")

Fixes: 58ac1b379979 ("ARM: PL011: Fix DMA support") Cc: stable stable@kernel.org Signed-off-by: Miaoqian Lin linmq006@gmail.com Reviewed-by: Gregory CLEMENT gregory.clement@bootlin.com Link: https://patch.msgid.link/20251027092053.87937-1-linmq006@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/tty/serial/amba-pl011.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -640,7 +640,7 @@ static int pl011_dma_tx_refill(struct ua dmatx->len = count; dmatx->dma = dma_map_single(dma_dev->dev, dmatx->buf, count, DMA_TO_DEVICE); - if (dmatx->dma == DMA_MAPPING_ERROR) { + if (dma_mapping_error(dma_dev->dev, dmatx->dma)) { uap->dmatx.queued = false; dev_dbg(uap->port.dev, "unable to map TX DMA\n"); return -EBUSY;