[source] kernel: spi: allow setting chipselect gpio to sleep

[LEDE Commits]

nbd pushed a commit to source.git, branch master:
https://git.lede-project.org/5f9e36712799e7737695384e3c82278af3ddf368

commit 5f9e36712799e7737695384e3c82278af3ddf368
Author: Felix Fietkau <nbd at nbd.name>
AuthorDate: Fri Dec 30 14:57:22 2016 +0100

    kernel: spi: allow setting chipselect gpio to sleep
    
    Fixes issues on some ar71xx MikroTik RouterBoard devices
    
    Signed-off-by: Felix Fietkau <nbd at nbd.name>
---
 ...io_set_value_cansleep-for-setting-chipsele.patch | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/target/linux/generic/patches-4.4/106-spi-use-gpio_set_value_cansleep-for-setting-chipsele.patch b/target/linux/generic/patches-4.4/106-spi-use-gpio_set_value_cansleep-for-setting-chipsele.patch
new file mode 100644
index 0000000..57c9475
--- /dev/null
+++ b/target/linux/generic/patches-4.4/106-spi-use-gpio_set_value_cansleep-for-setting-chipsele.patch
@@ -0,0 +1,21 @@
+From: Felix Fietkau <nbd at nbd.name>
+Date: Fri, 30 Dec 2016 14:53:45 +0100
+Subject: [PATCH] spi: use gpio_set_value_cansleep for setting chipselect GPIO
+
+Sleeping is safe inside spi_transfer_one_message, and some GPIO chips
+need to sleep for setting values
+
+Signed-off-by: Felix Fietkau <nbd at nbd.name>
+---
+
+--- a/drivers/spi/spi.c
++++ b/drivers/spi/spi.c
+@@ -674,7 +674,7 @@ static void spi_set_cs(struct spi_device
+ 		enable = !enable;
+ 
+ 	if (gpio_is_valid(spi->cs_gpio))
+-		gpio_set_value(spi->cs_gpio, !enable);
++		gpio_set_value_cansleep(spi->cs_gpio, !enable);
+ 	else if (spi->master->set_cs)
+ 		spi->master->set_cs(spi, !enable);
+ }