linux-kernel - [PATCH] spi: Fix incorrect cs

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Date:   Sat, 11 Dec 2021 00:36:34 +0900
From:   Hector Martin <marcan@...can.st>
To:     Mark Brown <broonie@...nel.org>,
        Alexandru Ardelean <alexandru.ardelean@...log.com>
Cc:     linux-spi@...r.kernel.org, linux-kernel@...r.kernel.org,
        Joey Gouly <joey.gouly@....com>,
        Hector Martin <marcan@...can.st>
Subject: [PATCH] spi: Fix incorrect cs_setup delay handling

We need to wait *after* asserting CS and before the transfer, not before
asserting CS which isn't very useful.

Fixes: 25093bdeb6bc ("spi: implement SW control for CS times")
Signed-off-by: Hector Martin <marcan@...can.st>
---
 drivers/spi/spi.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index b23e675953e1..cfb708d928b5 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -947,12 +947,9 @@ static void spi_set_cs(struct spi_device *spi, bool enable, bool force)
 	spi->controller->last_cs_enable = enable;
 	spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH;
 
-	if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio) ||
-	    !spi->controller->set_cs_timing) {
-		if (activate)
-			spi_delay_exec(&spi->cs_setup, NULL);
-		else
-			spi_delay_exec(&spi->cs_hold, NULL);
+	if ((spi->cs_gpiod || gpio_is_valid(spi->cs_gpio) ||
+	    !spi->controller->set_cs_timing) && !activate) {
+		spi_delay_exec(&spi->cs_hold, NULL);
 	}
 
 	if (spi->mode & SPI_CS_HIGH)
@@ -994,7 +991,9 @@ static void spi_set_cs(struct spi_device *spi, bool enable, bool force)
 
 	if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio) ||
 	    !spi->controller->set_cs_timing) {
-		if (!activate)
+		if (activate)
+			spi_delay_exec(&spi->cs_setup, NULL);
+		else
 			spi_delay_exec(&spi->cs_inactive, NULL);
 	}
 }
-- 
2.33.0