mmc: dw_mmc: fix stop when fallen back to PIO
There are several situations when dw_mci_submit_data_dma() decides to
fall back to PIO mode instead of using DMA, due to a short (to avoid
overhead) or "complex" (e.g. with unaligned buffers) transaction, even
though host->use_dma is set. However dw_mci_stop_dma() decides whether
to stop DMA or set the EVENT_XFER_COMPLETE event based on host->use_dma.
When falling back to PIO mode this results in data timeout errors
getting missed and the driver locking up.
Therefore add host->using_dma to indicate whether the current
transaction is using dma or not, and adjust dw_mci_stop_dma() to use
that instead.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Will Newton <will.newton@imgtec.com>
Tested-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/include/linux/mmc/dw_mmc.h b/include/linux/mmc/dw_mmc.h
index f3f68ee..6b46819 100644
--- a/include/linux/mmc/dw_mmc.h
+++ b/include/linux/mmc/dw_mmc.h
@@ -48,6 +48,7 @@
* @data: The data currently being transferred, or NULL if no data
* transfer is in progress.
* @use_dma: Whether DMA channel is initialized or not.
+ * @using_dma: Whether DMA is in use for the current transfer.
* @sg_dma: Bus address of DMA buffer.
* @sg_cpu: Virtual address of DMA buffer.
* @dma_ops: Pointer to platform-specific DMA callbacks.
@@ -121,6 +122,7 @@
/* DMA interface members*/
int use_dma;
+ int using_dma;
dma_addr_t sg_dma;
void *sg_cpu;