mmc: sdhci: use WP GPIO in sdhci_check_ro()

Hello Thomas Petazzoni,

The patch 6d5cd068ee59: "mmc: sdhci: use WP GPIO in sdhci_check_ro()" from Feb 12, 2019, leads to the following static checker warning:

drivers/gpio/gpiolib.c:3287 gpiod_get_value_cansleep()
warn: sleeping in atomic context

drivers/mmc/host/sdhci.c
2424 static int sdhci_check_ro(struct sdhci_host *host) 2425 {
2426 unsigned long flags;
2427 int is_readonly;
2428

  2429          spin_lock_irqsave(&host->lock, flags);
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

We're holding a spin lock.

2430
2431 if (host->flags & SDHCI_DEVICE_DEAD)
2432 is_readonly = 0;
2433 else if (host->ops->get_ro)
2434 is_readonly = host->ops->get_ro(host);
2435 else if (mmc_can_gpio_ro(host->mmc))

  2436                  is_readonly = mmc_gpio_get_ro(host->mmc);
                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^

The mmc_gpio_get_ro() function calls gpiod_get_value_cansleep() which, as the name suggests, can sleep.

2437 else
2438 is_readonly = !(sdhci_readl(host, SDHCI_PRESENT_STATE)
2439 & SDHCI_WRITE_PROTECT);
2440
2441 spin_unlock_irqrestore(&host->lock, flags);
2442
2443 /* This quirk needs to be replaced by a callback-function later */
2444 return host->quirks & SDHCI_QUIRK_INVERTED_WRITE_PROTECT ?
2445 !is_readonly : is_readonly;
2446 }

regards,
dan carpenter