From e106853286f90afbcbcc9e4daec8632bf39ebc92 Mon Sep 17 00:00:00 2001
From: Tudor Ambarus <tudor.ambarus@microchip.com>
Date: Wed, 19 Jun 2019 14:38:28 +0000
Subject: [PATCH] spi: fix ctrl->num_chipselect constraint
at91sam9g25ek showed the following error at probe:
atmel_spi f0000000.spi: Using dma0chan2 (tx) and dma0chan3 (rx)
for DMA transfers
atmel_spi: probe of f0000000.spi failed with error -22
Commit 2c2b566173d5 ("spi: Don't call spi_get_gpio_descs() before device name is set")
moved the calling of spi_get_gpio_descs() after ctrl->dev is set,
but didn't move the !ctrl->num_chipselect check. When there are
chip selects in the device tree, the spi-atmel driver lets the
SPI core discover them when registering the SPI master.
The ctrl->num_chipselect is thus expected to be set by
spi_get_gpio_descs().
Move the !ctlr->num_chipselect after spi_get_gpio_descs() as it was
before the aforementioned commit. While touching this block, get rid
of the explicit comparison with 0 and update the commenting style.
Fixes: 2c2b566173d5 ("spi: Don't call spi_get_gpio_descs() before device name is set")
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
drivers/spi/spi.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index a31e1e2913359..80d2d14f62944 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -2375,11 +2375,6 @@ int spi_register_controller(struct spi_controller *ctlr)
if (status)
return status;
- /* even if it's just one always-selected device, there must
- * be at least one chipselect
- */
- if (ctlr->num_chipselect == 0)
- return -EINVAL;
if (ctlr->bus_num >= 0) {
/* devices with a fixed bus num must check-in with the num */
mutex_lock(&board_lock);
@@ -2450,6 +2445,13 @@ int spi_register_controller(struct spi_controller *ctlr)
}
}
+ /*
+ * Even if it's just one always-selected device, there must
+ * be at least one chipselect.
+ */
+ if (!ctlr->num_chipselect)
+ return -EINVAL;
+
status = device_add(&ctlr->dev);
if (status < 0) {
/* free bus id */
--
2.39.5