usb_storage: fix ehci driver max transfer size
The commit 5dd95cf93dfffa1d19a1928990852aac9f55b9d9 'usb_storage:
Fix EHCI "out of buffer pointers" with CD-ROM' introduce a bug in
usb_storage as it wrongly assumes that every transfer can use
4096 bytes per qt_buffer. This is wrong if the start address of
the data is not page aligned to 4096 bytes and leads to 'EHCI
timed out on TD' messages because of 'out of buffer pointers'
in ehci_td_buffer function.
The bug appears during load of a fragmented file and
read from or write to an unaligned memory address.
Cc: Marek Vasut <marex@denx.de>
Signed-off-by: Stefan Herbrechtsmeier <stefan@herbrechtsmeier.net>
diff --git a/common/usb_storage.c b/common/usb_storage.c
index faad237..bdc306f 100644
--- a/common/usb_storage.c
+++ b/common/usb_storage.c
@@ -150,12 +150,17 @@
unsigned int irqpipe; /* pipe for release_irq */
unsigned char irqmaxp; /* max packed for irq Pipe */
unsigned char irqinterval; /* Intervall for IRQ Pipe */
- unsigned long max_xfer_blk; /* Max blocks per xfer */
ccb *srb; /* current srb */
trans_reset transport_reset; /* reset routine */
trans_cmnd transport; /* transport routine */
};
+/*
+ * The U-Boot EHCI driver cannot handle more than 5 page aligned buffers
+ * of 4096 bytes in a transfer without running itself out of qt_buffers
+ */
+#define USB_MAX_XFER_BLK(start, blksz) (((4096 * 5) - (start % 4096)) / blksz)
+
static struct us_data usb_stor[USB_MAX_STOR_DEV];
@@ -1041,7 +1046,7 @@
unsigned long usb_stor_read(int device, unsigned long blknr,
unsigned long blkcnt, void *buffer)
{
- unsigned long start, blks, buf_addr;
+ unsigned long start, blks, buf_addr, max_xfer_blk;
unsigned short smallblks;
struct usb_device *dev;
struct us_data *ss;
@@ -1083,12 +1088,14 @@
/* XXX need some comment here */
retry = 2;
srb->pdata = (unsigned char *)buf_addr;
- if (blks > ss->max_xfer_blk)
- smallblks = ss->max_xfer_blk;
+ max_xfer_blk = USB_MAX_XFER_BLK(buf_addr,
+ usb_dev_desc[device].blksz);
+ if (blks > max_xfer_blk)
+ smallblks = (unsigned short) max_xfer_blk;
else
smallblks = (unsigned short) blks;
retry_it:
- if (smallblks == ss->max_xfer_blk)
+ if (smallblks == max_xfer_blk)
usb_show_progress();
srb->datalen = usb_dev_desc[device].blksz * smallblks;
srb->pdata = (unsigned char *)buf_addr;
@@ -1109,7 +1116,7 @@
start, smallblks, buf_addr);
usb_disable_asynch(0); /* asynch transfer allowed */
- if (blkcnt >= ss->max_xfer_blk)
+ if (blkcnt >= max_xfer_blk)
debug("\n");
return blkcnt;
}
@@ -1117,7 +1124,7 @@
unsigned long usb_stor_write(int device, unsigned long blknr,
unsigned long blkcnt, const void *buffer)
{
- unsigned long start, blks, buf_addr;
+ unsigned long start, blks, buf_addr, max_xfer_blk;
unsigned short smallblks;
struct usb_device *dev;
struct us_data *ss;
@@ -1162,12 +1169,14 @@
*/
retry = 2;
srb->pdata = (unsigned char *)buf_addr;
- if (blks > ss->max_xfer_blk)
- smallblks = ss->max_xfer_blk;
+ max_xfer_blk = USB_MAX_XFER_BLK(buf_addr,
+ usb_dev_desc[device].blksz);
+ if (blks > max_xfer_blk)
+ smallblks = (unsigned short) max_xfer_blk;
else
smallblks = (unsigned short) blks;
retry_it:
- if (smallblks == ss->max_xfer_blk)
+ if (smallblks == max_xfer_blk)
usb_show_progress();
srb->datalen = usb_dev_desc[device].blksz * smallblks;
srb->pdata = (unsigned char *)buf_addr;
@@ -1188,7 +1197,7 @@
start, smallblks, buf_addr);
usb_disable_asynch(0); /* asynch transfer allowed */
- if (blkcnt >= ss->max_xfer_blk)
+ if (blkcnt >= max_xfer_blk)
debug("\n");
return blkcnt;
@@ -1415,12 +1424,6 @@
USB_STOR_PRINTF(" address %d\n", dev_desc->target);
USB_STOR_PRINTF("partype: %d\n", dev_desc->part_type);
- /*
- * The U-Boot EHCI driver cannot handle more than 4096 * 5 bytes in a
- * transfer without running itself out of qt_buffers.
- */
- ss->max_xfer_blk = (4096 * 5) / dev_desc->blksz;
-
init_part(dev_desc);
USB_STOR_PRINTF("partype: %d\n", dev_desc->part_type);