From 162f43e31c5a376ec16336e5d0ac973373d54c89 Mon Sep 17 00:00:00 2001 From: Guennadi Liakhovetski Date: Thu, 14 Jul 2011 18:39:10 +0200 Subject: [PATCH] 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 Signed-off-by: Chris Ball --- drivers/mmc/host/tmio_mmc.h | 5 +++++ drivers/mmc/host/tmio_mmc_dma.c | 5 ++++- drivers/mmc/host/tmio_mmc_pio.c | 4 ++-- 3 files changed, 11 insertions(+), 3 deletions(-) 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 @@ static inline void tmio_mmc_kunmap_atomic(struct scatterlist *sg, #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_start_dma(struct tmio_mmc_host *host, { } +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 @@ int tmio_mmc_host_resume(struct device *dev) 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 @@ int tmio_mmc_host_runtime_resume(struct device *dev) 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 */ -- 2.7.4