[PATCH] ARM: mx3: Fix a race condition in mxcmmc
Volker Ernst
volker.ernst at txtr.com
Mon Apr 26 16:51:07 EDT 2010
This fixes a race condition regarding interrupt bits in the SDHC
controller driver code.
In case of PIO-transfer it does not clear SDHC-status bit#11/12
in the INT-handler anymore. INT-handler might be called during
an ongoing PIO-data-transfer (with some other INT-flag set) and
PIO-transfer depends on these bits being set to detect the end
of the data-transfer. This also means that at the end of PIO-
transfer that PIO-software has to clear these bits itself.
However in case of DMA-transfer these bits have to be cleared
in the INT-handler, because they are used to generate INTs then.
Works solid, no more problems here, can transfer big files.
Signed-off-by: Volker Ernst <volker.ernst at txtr.com>
Acked-by: Daniel Mack <daniel at caiaq.de>
Cc: Andy Green <andy at warmcat.com>
---
drivers/mmc/host/mxcmmc.c | 13 ++++++++++++-
1 files changed, 12 insertions(+), 1 deletions(-)
diff --git a/drivers/mmc/host/mxcmmc.c b/drivers/mmc/host/mxcmmc.c
index 2c53024..ec18e3b 100644
--- a/drivers/mmc/host/mxcmmc.c
+++ b/drivers/mmc/host/mxcmmc.c
@@ -489,6 +489,9 @@ static void mxcmci_datawork(struct work_struct *work)
struct mxcmci_host *host = container_of(work, struct mxcmci_host,
datawork);
int datastat = mxcmci_transfer_data(host);
+
+ writel(STATUS_READ_OP_DONE | STATUS_WRITE_OP_DONE,
+ host->base + MMC_REG_STATUS);
mxcmci_finish_data(host, datastat);
if (host->req->stop) {
@@ -553,7 +556,8 @@ static irqreturn_t mxcmci_irq(int irq, void *devid)
u32 stat;
stat = readl(host->base + MMC_REG_STATUS);
- writel(stat & ~STATUS_SDIO_INT_ACTIVE, host->base + MMC_REG_STATUS);
+ writel(stat & ~(STATUS_SDIO_INT_ACTIVE | STATUS_DATA_TRANS_DONE |
+ STATUS_WRITE_OP_DONE), host->base + MMC_REG_STATUS);
dev_dbg(mmc_dev(host->mmc), "%s: 0x%08x\n", __func__, stat);
@@ -561,6 +565,13 @@ static irqreturn_t mxcmci_irq(int irq, void *devid)
sdio_irq = (stat & STATUS_SDIO_INT_ACTIVE) && host->use_sdio;
spin_unlock_irqrestore(&host->lock, flags);
+#ifdef HAS_DMA
+ if (mxcmci_use_dma(host) &&
+ (stat & (STATUS_READ_OP_DONE | STATUS_WRITE_OP_DONE)))
+ writel(STATUS_READ_OP_DONE | STATUS_WRITE_OP_DONE,
+ host->base + MMC_REG_STATUS);
+#endif
+
if (sdio_irq) {
writel(STATUS_SDIO_INT_ACTIVE, host->base + MMC_REG_STATUS);
mmc_signal_sdio_irq(host->mmc);
--
1.7.0.3
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