[PATCH v2] mmc: slot-gpio: Fix missing assignment to ctx->ro_gpio

[Chris Ball <cjb@laptop.org>]

mmc_gpio_request_ro() doesn't store the requested gpio in ctx->ro_gpio.
As a result, subsequent calls to mmc_gpio_get_ro() will always fail
with -ENOSYS because the gpio number isn't available to that function.

Cc: stable <stable@vger.kernel.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
---
v2, addressing Guennadi's review comments:
 - If gpio_request_one() fails, ctx->ro_gpio shouldn't contain a
   valid GPIO number.

 drivers/mmc/core/slot-gpio.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/core/slot-gpio.c b/drivers/mmc/core/slot-gpio.c
index 0582429..08c6b3d 100644
--- a/drivers/mmc/core/slot-gpio.c
+++ b/drivers/mmc/core/slot-gpio.c
@@ -100,7 +100,13 @@ int mmc_gpio_request_ro(struct mmc_host *host, unsigned int gpio)
 
 	ctx = host->slot.handler_priv;
 
-	return gpio_request_one(gpio, GPIOF_DIR_IN, ctx->ro_label);
+	ret = gpio_request_one(gpio, GPIOF_DIR_IN, ctx->ro_label);
+	if (ret < 0)
+		return ret;
+
+	ctx->ro_gpio = gpio;
+
+	return 0;
 }
 EXPORT_SYMBOL(mmc_gpio_request_ro);
 
-- 
Chris Ball   <cjb@laptop.org>   <http://printf.net/>
One Laptop Per Child