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path: root/drivers/usb/musb/musbhsdma.c
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Diffstat (limited to 'drivers/usb/musb/musbhsdma.c')
-rw-r--r--drivers/usb/musb/musbhsdma.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/usb/musb/musbhsdma.c b/drivers/usb/musb/musbhsdma.c
index 6f771af5cbd..563114d613d 100644
--- a/drivers/usb/musb/musbhsdma.c
+++ b/drivers/usb/musb/musbhsdma.c
@@ -158,6 +158,8 @@ static int dma_channel_program(struct dma_channel *channel,
dma_addr_t dma_addr, u32 len)
{
struct musb_dma_channel *musb_channel = channel->private_data;
+ struct musb_dma_controller *controller = musb_channel->controller;
+ struct musb *musb = controller->private_data;
DBG(2, "ep%d-%s pkt_sz %d, dma_addr 0x%x length %d, mode %d\n",
musb_channel->epnum,
@@ -167,6 +169,18 @@ static int dma_channel_program(struct dma_channel *channel,
BUG_ON(channel->status == MUSB_DMA_STATUS_UNKNOWN ||
channel->status == MUSB_DMA_STATUS_BUSY);
+ /*
+ * The DMA engine in RTL1.8 and above cannot handle
+ * DMA addresses that are not aligned to a 4 byte boundary.
+ * It ends up masking the last two bits of the address
+ * programmed in DMA_ADDR.
+ *
+ * Fail such DMA transfers, so that the backup PIO mode
+ * can carry out the transfer
+ */
+ if ((musb->hwvers >= MUSB_HWVERS_1800) && (dma_addr % 4))
+ return false;
+
channel->actual_len = 0;
musb_channel->start_addr = dma_addr;
musb_channel->len = len;