mmc: sdhci: Test cd-gpio instead of SDHCI presence when probing

Previously to this patch, an SDHCI platform that uses a GPIO for
card detection instead of the internal SDHCI_CARD_PRESENT bit on
the presence register would fail to detect a new card.

Some drivers worked around this in various ways: esdhc-imx defines
an IO accessor to fake the presence bit being true, s3c turns on
polling (which stops the SDHCI driver from checking the bit) after
a card's inserted.  But none of this should be necessary; the real
fix is to check whether we're using a GPIO and avoid relying on
the presence bit if so, as this patch implements.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
This commit is contained in:
Guennadi Liakhovetski 2012-09-17 16:45:10 +08:00 committed by Chris Ball
parent 5413da811f
commit bec9d4e593

View File

@ -28,6 +28,7 @@
#include <linux/mmc/mmc.h>
#include <linux/mmc/host.h>
#include <linux/mmc/card.h>
#include <linux/mmc/slot-gpio.h>
#include "sdhci.h"
@ -1293,6 +1294,13 @@ static void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq)
present = sdhci_readl(host, SDHCI_PRESENT_STATE) &
SDHCI_CARD_PRESENT;
/* If we're using a cd-gpio, testing the presence bit might fail. */
if (!present) {
int ret = mmc_gpio_get_cd(host->mmc);
if (ret > 0)
present = true;
}
if (!present || host->flags & SDHCI_DEVICE_DEAD) {
host->mrq->cmd->error = -ENOMEDIUM;
tasklet_schedule(&host->finish_tasklet);