3 files changed, 37 insertions, 0 deletions

diff --git a/drivers/usb/musb/blackfin.c b/drivers/usb/musb/blackfin.c
index 52312e8af213..8e2a1ff8a35a 100644
--- a/drivers/usb/musb/blackfin.c
+++ b/drivers/usb/musb/blackfin.c
@@ -21,6 +21,7 @@
 #include <asm/cacheflush.h>
 
 #include "musb_core.h"
+#include "musbhsdma.h"
 #include "blackfin.h"
 
 struct bfin_glue {
@@ -332,6 +333,27 @@ static int bfin_musb_set_mode(struct musb *musb, u8 musb_mode)
         return -EIO;
 }
 
+static int bfin_musb_adjust_channel_params(struct dma_channel *channel,
+                                u16 packet_sz, u8 *mode,
+                                dma_addr_t *dma_addr, u32 *len)
+{
+        struct musb_dma_channel *musb_channel = channel->private_data;
+
+        /*
+         * Anomaly 05000450 might cause data corruption when using DMA
+         * MODE 1 transmits with short packet.  So to work around this,
+         * we truncate all MODE 1 transfers down to a multiple of the
+         * max packet size, and then do the last short packet transfer
+         * (if there is any) using MODE 0.
+         */
+        if (ANOMALY_05000450) {
+                if (musb_channel->transmit && *mode == 1)
+                        *len = *len - (*len % packet_sz);
+        }
+
+        return 0;
+}
+
 static void bfin_musb_reg_init(struct musb *musb)
 {
         if (ANOMALY_05000346) {
@@ -430,6 +452,8 @@ static const struct musb_platform_ops bfin_ops = {
 
         .vbus_status    = bfin_musb_vbus_status,
         .set_vbus       = bfin_musb_set_vbus,
+
+        .adjust_channel_params = bfin_musb_adjust_channel_params,
 };
 
 static u64 bfin_dmamask = DMA_BIT_MASK(32);
diff --git a/drivers/usb/musb/musb_core.h b/drivers/usb/musb/musb_core.h
index 4bd9e2145ee4..0e053b587960 100644
--- a/drivers/usb/musb/musb_core.h
+++ b/drivers/usb/musb/musb_core.h
@@ -261,6 +261,7 @@ enum musb_g_ep0_state {
  * @try_ilde:   tries to idle the IP
  * @vbus_status: returns vbus status if possible
  * @set_vbus:   forces vbus status
+ * @channel_program: pre check for standard dma channel_program func
  */
 struct musb_platform_ops {
         int     (*init)(struct musb *musb);
@@ -274,6 +275,10 @@ struct musb_platform_ops {
 
         int     (*vbus_status)(struct musb *musb);
         void    (*set_vbus)(struct musb *musb, int on);
+
+        int     (*adjust_channel_params)(struct dma_channel *channel,
+                                u16 packet_sz, u8 *mode,
+                                dma_addr_t *dma_addr, u32 *len);
 };
 
 /*
diff --git a/drivers/usb/musb/musbhsdma.c b/drivers/usb/musb/musbhsdma.c
index 0144a2d481fd..d281792db05c 100644
--- a/drivers/usb/musb/musbhsdma.c
+++ b/drivers/usb/musb/musbhsdma.c
@@ -169,6 +169,14 @@ static int dma_channel_program(struct dma_channel *channel,
         BUG_ON(channel->status == MUSB_DMA_STATUS_UNKNOWN ||
                 channel->status == MUSB_DMA_STATUS_BUSY);
 
+        /* Let targets check/tweak the arguments */
+        if (musb->ops->adjust_channel_params) {
+                int ret = musb->ops->adjust_channel_params(channel,
+                        packet_sz, &mode, &dma_addr, &len);
+                if (ret)
+                        return ret;
+        }
+
         /*
          * The DMA engine in RTL1.8 and above cannot handle
          * DMA addresses that are not aligned to a 4 byte boundary.