[PATCH 3.14 044/140] USB: io_ti: fix firmware download on big-endian machines

Greg Kroah-Hartman
2014-05-29T05:33:37Z

From: Johan Hovold <jhovold@gmail.com>

commit 5509076d1b4485ce9fb07705fcbcd2695907ab5b upstream.

During firmware download the device expects memory addresses in
big-endian byte order. As the wIndex parameter which hold the address is
sent in little-endian byte order regardless of host byte order, we need
to use swab16 rather than cpu_to_be16.

Also make sure to handle the struct ti_i2c_desc size parameter which is
returned in little-endian byte order.

Reported-by: Ludovic Drolez <ldrolez@debian.org>
Tested-by: Ludovic Drolez <ldrolez@debian.org>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/usb/serial/io_ti.c | 50 +++++++++++++++++++++++++++++----------------
1 file changed, 33 insertions(+), 17 deletions(-)

--- a/drivers/usb/serial/io_ti.c
+++ b/drivers/usb/serial/io_ti.c
@@ -28,6 +28,7 @@
#include <linux/spinlock.h>
#include <linux/mutex.h>
#include <linux/serial.h>
+#include <linux/swab.h>
#include <linux/kfifo.h>
#include <linux/ioctl.h>
#include <linux/firmware.h>
@@ -280,7 +281,7 @@ static int read_download_mem(struct usb_
{
int status = 0;
__u8 read_length;
- __be16 be_start_address;
+ u16 be_start_address;

dev_dbg(&dev->dev, "%s - @ %x for %d\n", __func__, start_address, length);

@@ -296,10 +297,14 @@ static int read_download_mem(struct usb_
if (read_length > 1) {
dev_dbg(&dev->dev, "%s - @ %x for %d\n", __func__, start_address, read_length);
}
- be_start_address = cpu_to_be16(start_address);
+ /*
+ * NOTE: Must use swab as wIndex is sent in little-endian
+ * byte order regardless of host byte order.
+ */
+ be_start_address = swab16((u16)start_address);
status = ti_vread_sync(dev, UMPC_MEMORY_READ,
(__u16)address_type,
- (__force __u16)be_start_address,
+ be_start_address,
buffer, read_length);

if (status) {
@@ -394,7 +399,7 @@ static int write_i2c_mem(struct edgeport
struct device *dev = &serial->serial->dev->dev;
int status = 0;
int write_length;
- __be16 be_start_address;
+ u16 be_start_address;

/* We can only send a maximum of 1 aligned byte page at a time */

@@ -409,11 +414,16 @@ static int write_i2c_mem(struct edgeport
__func__, start_address, write_length);
usb_serial_debug_data(dev, __func__, write_length, buffer);

- /* Write first page */
- be_start_address = cpu_to_be16(start_address);
+ /*
+ * Write first page.
+ *
+ * NOTE: Must use swab as wIndex is sent in little-endian byte order
+ * regardless of host byte order.
+ */
+ be_start_address = swab16((u16)start_address);
status = ti_vsend_sync(serial->serial->dev,
UMPC_MEMORY_WRITE, (__u16)address_type,
- (__force __u16)be_start_address,
+ be_start_address,
buffer, write_length);
if (status) {
dev_dbg(dev, "%s - ERROR %d\n", __func__, status);
@@ -436,11 +446,16 @@ static int write_i2c_mem(struct edgeport
__func__, start_address, write_length);
usb_serial_debug_data(dev, __func__, write_length, buffer);

- /* Write next page */
- be_start_address = cpu_to_be16(start_address);
+ /*
+ * Write next page.
+ *
+ * NOTE: Must use swab as wIndex is sent in little-endian byte
+ * order regardless of host byte order.
+ */
+ be_start_address = swab16((u16)start_address);
status = ti_vsend_sync(serial->serial->dev, UMPC_MEMORY_WRITE,
(__u16)address_type,
- (__force __u16)be_start_address,
+ be_start_address,
buffer, write_length);
if (status) {
dev_err(dev, "%s - ERROR %d\n", __func__, status);
@@ -585,8 +600,8 @@ static int get_descriptor_addr(struct ed
if (rom_desc->Type == desc_type)
return start_address;

- start_address = start_address + sizeof(struct ti_i2c_desc)
- + rom_desc->Size;
+ start_address = start_address + sizeof(struct ti_i2c_desc) +
+ le16_to_cpu(rom_desc->Size);

} while ((start_address < TI_MAX_I2C_SIZE) && rom_desc->Type);

@@ -599,7 +614,7 @@ static int valid_csum(struct ti_i2c_desc
__u16 i;
__u8 cs = 0;

- for (i = 0; i < rom_desc->Size; i++)
+ for (i = 0; i < le16_to_cpu(rom_desc->Size); i++)
cs = (__u8)(cs + buffer[i]);

if (cs != rom_desc->CheckSum) {
@@ -650,7 +665,7 @@ static int check_i2c_image(struct edgepo
break;

if ((start_address + sizeof(struct ti_i2c_desc) +
- rom_desc->Size) > TI_MAX_I2C_SIZE) {
+ le16_to_cpu(rom_desc->Size)) > TI_MAX_I2C_SIZE) {
status = -ENODEV;
dev_dbg(dev, "%s - structure too big, erroring out.\n", __func__);
break;
@@ -665,7 +680,8 @@ static int check_i2c_image(struct edgepo
/* Read the descriptor data */
status = read_rom(serial, start_address +
sizeof(struct ti_i2c_desc),
- rom_desc->Size, buffer);
+ le16_to_cpu(rom_desc->Size),
+ buffer);
if (status)
break;

@@ -674,7 +690,7 @@ static int check_i2c_image(struct edgepo
break;
}
start_address = start_address + sizeof(struct ti_i2c_desc) +
- rom_desc->Size;
+ le16_to_cpu(rom_desc->Size);

} while ((rom_desc->Type != I2C_DESC_TYPE_ION) &&
(start_address < TI_MAX_I2C_SIZE));
@@ -712,7 +728,7 @@ static int get_manuf_info(struct edgepor

/* Read the descriptor data */
status = read_rom(serial, start_address+sizeof(struct ti_i2c_desc),
- rom_desc->Size, buffer);
+ le16_to_cpu(rom_desc->Size), buffer);
if (status)
goto exit;