[PATCH v2] mtd: onenand: samsung: report DMA completion timeouts

[Pengpeng Hou]

The S5PC110 OneNAND DMA helpers have bounded waits for transfer
completion. The polling helper falls out of its timeout loop and returns
success, and the IRQ helper ignores wait_for_completion_timeout().

Return -ETIMEDOUT when the DMA transfer-done bit or completion does not
arrive before the timeout so callers can treat the buffer transfer as
failed.

Fixes: e23abf4b7743 ("mtd: OneNAND: S5PC110: Implement DMA interrupt method")
Cc: stable at vger.kernel.org
Signed-off-by: Pengpeng Hou <pengpeng at iscas.ac.cn>
---
Changes since v1: https://lore.kernel.org/all/20260623061233.40188-1-pengpeng@iscas.ac.cn/
- add Fixes and Cc stable tags as requested by Miquel

 drivers/mtd/nand/onenand/onenand_samsung.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/nand/onenand/onenand_samsung.c b/drivers/mtd/nand/onenand/onenand_samsung.c
index 6d6aa709a21f..b7b7758ce4d8 100644
--- a/drivers/mtd/nand/onenand/onenand_samsung.c
+++ b/drivers/mtd/nand/onenand/onenand_samsung.c
@@ -554,6 +554,9 @@ static int s5pc110_dma_poll(dma_addr_t dst, dma_addr_t src, size_t count, int di
 	} while (!(status & S5PC110_DMA_TRANS_STATUS_TD) &&
 		time_before(jiffies, timeout));
 
+	if (!(status & S5PC110_DMA_TRANS_STATUS_TD))
+		return -ETIMEDOUT;
+
 	writel(S5PC110_DMA_TRANS_CMD_TDC, base + S5PC110_DMA_TRANS_CMD);
 
 	return 0;
@@ -608,7 +611,9 @@ static int s5pc110_dma_irq(dma_addr_t dst, dma_addr_t src, size_t count, int dir
 
 	writel(S5PC110_DMA_TRANS_CMD_TR, base + S5PC110_DMA_TRANS_CMD);
 
-	wait_for_completion_timeout(&onenand->complete, msecs_to_jiffies(20));
+	if (!wait_for_completion_timeout(&onenand->complete,
+					 msecs_to_jiffies(20)))
+		return -ETIMEDOUT;
 
 	return 0;
 }
-- 
2.53.0