USB: Use (get|put)_unaligned for accessing wMaxPacketSize
In 9792987721c7980453fe6447c3fa6593b44f8458 Stefan describes a usecase
where the previous behavior of leaving wMaxPacketSize be unaligned
caused fatal problems. The initial fix for this problem was incomplete
however as it showed another cases of non-aligned access that previously
worked implicitly. This switches to making sure that all access of
wMaxPacketSize are done via (get|put)_unaligned.
In order to maintain a level of readability to the code in some cases
we now use a variable for the value of wMaxPacketSize and in others, a
macro.
Cc: Minkyu Kang <mk7.kang@samsung.com>
Cc: Remy Bohmer <linux@bohmer.net>
OpenRISC:
Tested-by: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Beagleboard xM, Pandaboard run-tested, s5p_goni build-tested.
Signed-off-by: Tom Rini <trini@ti.com>
diff --git a/drivers/usb/gadget/epautoconf.c b/drivers/usb/gadget/epautoconf.c
index 1896489..5b8776e 100644
--- a/drivers/usb/gadget/epautoconf.c
+++ b/drivers/usb/gadget/epautoconf.c
@@ -25,6 +25,7 @@
#include <linux/usb/ch9.h>
#include <asm/errno.h>
#include <linux/usb/gadget.h>
+#include <asm/unaligned.h>
#include "gadget_chips.h"
#define isdigit(c) ('0' <= (c) && (c) <= '9')
@@ -127,7 +128,7 @@
* where it's an output parameter representing the full speed limit.
* the usb spec fixes high speed bulk maxpacket at 512 bytes.
*/
- max = 0x7ff & le16_to_cpu(desc->wMaxPacketSize);
+ max = 0x7ff & le16_to_cpu(get_unaligned(&desc->wMaxPacketSize));
switch (type) {
case USB_ENDPOINT_XFER_INT:
/* INT: limit 64 bytes full speed, 1024 high speed */
@@ -143,7 +144,8 @@
return 0;
/* BOTH: "high bandwidth" works only at high speed */
- if ((desc->wMaxPacketSize & __constant_cpu_to_le16(3<<11))) {
+ if ((get_unaligned(&desc->wMaxPacketSize) &
+ __constant_cpu_to_le16(3<<11))) {
if (!gadget->is_dualspeed)
return 0;
/* configure your hardware with enough buffering!! */
@@ -176,7 +178,7 @@
/* min() doesn't work on bitfields with gcc-3.5 */
if (size > 64)
size = 64;
- desc->wMaxPacketSize = cpu_to_le16(size);
+ put_unaligned(cpu_to_le16(size), &desc->wMaxPacketSize);
}
return 1;
}