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From:   Nam Cao <namcao@linutronix.de>
To:     linus.walleij@linaro.org, broonie@kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-spi@vger.kernel.org,
        linux-kernel@vger.kernel.org
Cc:     Nam Cao <namcao@linutronix.de>
Subject: [PATCH 1/2] spi: introduce SPI_TRANS_FAIL_IO for error reporting
Date:   Wed, 29 Nov 2023 14:32:18 +0100
Message-Id: <361901574eec1271c0969edba6492d3f2132fade.1701264413.git.namcao@linutronix.de>
In-Reply-To: <cover.1701264413.git.namcao@linutronix.de>
References: <cover.1701264413.git.namcao@linutronix.de>
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The default message transfer implementation - spi_transfer_one_message -
invokes the specific device driver's transfer_one(), then waits for
completion. However, there is no mechanism for the device driver to
report failure in the middle of the transfer.

Introduce SPI_TRANS_FAIL_IO for drivers to report transfer failure.

Signed-off-by: Nam Cao <namcao@linutronix.de>
---
 drivers/spi/spi.c       | 3 +++
 include/linux/spi/spi.h | 1 +
 2 files changed, 4 insertions(+)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 8ead7acb99f3..a4b8c07c5951 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1361,6 +1361,9 @@ static int spi_transfer_wait(struct spi_controller *c=
tlr,
 				"SPI transfer timed out\n");
 			return -ETIMEDOUT;
 		}
+
+		if (xfer->error & SPI_TRANS_FAIL_IO)
+			return -EIO;
 	}
=20
 	return 0;
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index 7b4baff63c5c..ddadae2e1ead 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -1040,6 +1040,7 @@ struct spi_transfer {
 	unsigned	len;
=20
 #define SPI_TRANS_FAIL_NO_START	BIT(0)
+#define SPI_TRANS_FAIL_IO	BIT(1)
 	u16		error;
=20
 	dma_addr_t	tx_dma;
--=20
2.39.2