mmc: tmio: fix a deadlock
Currently the tmio-mmc driver contains a recursive runtime PM method
invocation, which leads to a deadlock on a mutex. Avoid it by taking
care not to request DMA too early.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/drivers/mmc/host/tmio_mmc.h b/drivers/mmc/host/tmio_mmc.h
index ba0d8e6..087d880 100644
--- a/drivers/mmc/host/tmio_mmc.h
+++ b/drivers/mmc/host/tmio_mmc.h
@@ -109,6 +109,7 @@
#if defined(CONFIG_MMC_SDHI) || defined(CONFIG_MMC_SDHI_MODULE)
void tmio_mmc_start_dma(struct tmio_mmc_host *host, struct mmc_data *data);
+void tmio_mmc_enable_dma(struct tmio_mmc_host *host, bool enable);
void tmio_mmc_request_dma(struct tmio_mmc_host *host, struct tmio_mmc_data *pdata);
void tmio_mmc_release_dma(struct tmio_mmc_host *host);
#else
@@ -117,6 +118,10 @@
{
}
+static inline void tmio_mmc_enable_dma(struct tmio_mmc_host *host, bool enable)
+{
+}
+
static inline void tmio_mmc_request_dma(struct tmio_mmc_host *host,
struct tmio_mmc_data *pdata)
{
diff --git a/drivers/mmc/host/tmio_mmc_dma.c b/drivers/mmc/host/tmio_mmc_dma.c
index 7e86662..2aa616d 100644
--- a/drivers/mmc/host/tmio_mmc_dma.c
+++ b/drivers/mmc/host/tmio_mmc_dma.c
@@ -22,8 +22,11 @@
#define TMIO_MMC_MIN_DMA_LEN 8
-static void tmio_mmc_enable_dma(struct tmio_mmc_host *host, bool enable)
+void tmio_mmc_enable_dma(struct tmio_mmc_host *host, bool enable)
{
+ if (!host->chan_tx || !host->chan_rx)
+ return;
+
#if defined(CONFIG_SUPERH) || defined(CONFIG_ARCH_SHMOBILE)
/* Switch DMA mode on or off - SuperH specific? */
sd_ctrl_write16(host, CTL_DMA_ENABLE, enable ? 2 : 0);
diff --git a/drivers/mmc/host/tmio_mmc_pio.c b/drivers/mmc/host/tmio_mmc_pio.c
index 221ffb7..1f16357 100644
--- a/drivers/mmc/host/tmio_mmc_pio.c
+++ b/drivers/mmc/host/tmio_mmc_pio.c
@@ -984,7 +984,7 @@
if (host->pm_global) {
/* Runtime PM resume callback didn't run */
tmio_mmc_reset(host);
- tmio_mmc_request_dma(host, host->pdata);
+ tmio_mmc_enable_dma(host, true);
host->pm_global = false;
}
@@ -1007,7 +1007,7 @@
struct tmio_mmc_data *pdata = host->pdata;
tmio_mmc_reset(host);
- tmio_mmc_request_dma(host, host->pdata);
+ tmio_mmc_enable_dma(host, true);
if (pdata->power) {
/* Only entered after a card-insert interrupt */