From: Guennadi Liakhovetski <g.liakhovetski@xxxxxx>
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 bring up a new card because
logic in sdhci_request() fails the request if that bit is 0.
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: Chris Ball <cjb@xxxxxxxxxx>
---
drivers/mmc/host/sdhci.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index d98b199..0e15c79 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -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);
--
1.7.11.2
- Chris.
--
Chris Ball <cjb@xxxxxxxxxx> <http://printf.net/>
One Laptop Per Child
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