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[v3,8/9] spi: spi-s3c64xx: Increase transfer timeout

Message ID 20201002122243.26849-9-l.stelmach@samsung.com (mailing list archive)
State New, archived
Headers show
Series [v3,1/9] spi: spi-s3c64xx: swap s3c64xx_spi_set_cs() and s3c64xx_enable_datapath() | expand

Commit Message

Lukasz Stelmach Oct. 2, 2020, 12:22 p.m. UTC 
Increase timeout by 30 ms for some wiggle room and set the minimum value
to 100 ms. This ensures a non-zero value for short transfers which
may take less than 1 ms. The timeout value does not affect
performance because it is used with a completion.

Similar formula is used in other drivers e.g. sun4i, sun6i.

Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>
---
 drivers/spi/spi-s3c64xx.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 0bd3e230350c..9f728a7c59a1 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -473,7 +473,8 @@  static int s3c64xx_wait_for_dma(struct s3c64xx_spi_driver_data *sdd,
 
 	/* millisecs to xfer 'len' bytes @ 'cur_speed' */
 	ms = xfer->len * 8 * 1000 / sdd->cur_speed;
-	ms += 10; /* some tolerance */
+	ms += 30;               /* some tolerance */
+	ms = max(ms, 100);      /* minimum timeout */
 
 	val = msecs_to_jiffies(ms) + 10;
 	val = wait_for_completion_timeout(&sdd->xfer_completion, val);