USB: io_ti: fix firmware download on big-endian machines

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>
Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/serial/io_ti.c b/drivers/usb/serial/io_ti.c
index a2db5be..df90dae 100644 (file)
--- 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_device *dev, int start_address,
 {
        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_device *dev, int start_address,
                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_serial *serial,
        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_serial *serial,
                __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_serial *serial,
                        __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 edgeport_serial *serial,
                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 *rom_desc, __u8 *buffer)
        __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 edgeport_serial *serial)
                        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 edgeport_serial *serial)
                        /* 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 edgeport_serial *serial)
                                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 edgeport_serial *serial, __u8 *buffer)
 
        /* 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;