[PATCH v3 1/2] mmc: mmci.c: Defer probe() in case of yet uninitialized GPIOs

Roland Stigge
2012-06-17T10:12:31Z

If the GPIOs used by the MMCI driver are not registered yet when the driver is
probe()d, they can't be used. This happens if the mmci driver is probed before
the respective GPIO controller (e.g. on the LPC32xx EA3250 board, the PCA9532
GPIO controller would be initialized via DT after mmci). Therefore, we defer
mmci in this case.

Signed-off-by: Roland Stigge <stigge@antcom.de>

---
drivers/mmc/host/mmci.c | 8 ++++++++
1 file changed, 8 insertions(+)

--- linux-2.6.orig/drivers/mmc/host/mmci.c
+++ linux-2.6/drivers/mmc/host/mmci.c
@@ -1424,6 +1424,10 @@ static int __devinit mmci_probe(struct a
writel(0, host->base + MMCIMASK1);
writel(0xfff, host->base + MMCICLEAR);

+ if (plat->gpio_cd == -EPROBE_DEFER) {
+ ret = -EPROBE_DEFER;
+ goto err_gpio_cd;
+ }
if (gpio_is_valid(plat->gpio_cd)) {
ret = gpio_request(plat->gpio_cd, DRIVER_NAME " (cd)");
if (ret == 0)
@@ -1447,6 +1451,10 @@ static int __devinit mmci_probe(struct a
if (ret >= 0)
host->gpio_cd_irq = gpio_to_irq(plat->gpio_cd);
}
+ if (plat->gpio_wp == -EPROBE_DEFER) {
+ ret = -EPROBE_DEFER;
+ goto err_gpio_wp;
+ }
if (gpio_is_valid(plat->gpio_wp)) {
ret = gpio_request(plat->gpio_wp, DRIVER_NAME " (wp)");
if (ret == 0)