A recent patch that purported to fix firmware download on big-endian
machines failed to add the corresponding sparse annotation to the
i2c-header. This was reported by the kbuild test robot.
Adding the appropriate annotation revealed another endianess bug related
to the i2c-header Size-field in a code path that is exercised when the
firmware is actually being downloaded (and not just verified and left
untouched unless older than the firmware at hand).
This patch adds the required sparse annotation to the i2c-header and
makes sure that the Size-field is sent in little-endian byte order
during firmware download also on big-endian machines.
Note that this patch is only compile-tested, but that there is no
functional change for little-endian systems.
Reported-by: kbuild test robot <fengguang.wu@xxxxxxxxx>
Cc: Ludovic Drolez <ldrolez@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Johan Hovold <jhovold@xxxxxxxxx>
---
Turns out there was at least one more endianess bug in this driver
(which I should have found earlier had I not forgotten to add the
corresponding sparse annotation).
Not sure why fw-download appears to work without it -- perhaps the
device ignores the size field (14850 bytes would have been sent as 570
bytes on a big-endian machine).
Ludovic, could you test this patch as well with debugging enabled (did
you get that to work, btw?) and post a log? I'm curious about whether
this code path was actually executed or not (I assume it has to be).
Thanks,
Johan
drivers/usb/serial/io_ti.c | 2 +-
drivers/usb/serial/io_usbvend.h | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/serial/io_ti.c b/drivers/usb/serial/io_ti.c
index df90dae53eb9..c0a42e9e6777 100644
--- a/drivers/usb/serial/io_ti.c
+++ b/drivers/usb/serial/io_ti.c
@@ -821,7 +821,7 @@ static int build_i2c_fw_hdr(__u8 *header, struct device *dev)
firmware_rec = (struct ti_i2c_firmware_rec*)i2c_header->Data;
i2c_header->Type = I2C_DESC_TYPE_FIRMWARE_BLANK;
- i2c_header->Size = (__u16)buffer_size;
+ i2c_header->Size = cpu_to_le16(buffer_size);
i2c_header->CheckSum = cs;
firmware_rec->Ver_Major = OperationalMajorVersion;
firmware_rec->Ver_Minor = OperationalMinorVersion;
diff --git a/drivers/usb/serial/io_usbvend.h b/drivers/usb/serial/io_usbvend.h
index 51f83fbb73bb..6f6a856bc37c 100644
--- a/drivers/usb/serial/io_usbvend.h
+++ b/drivers/usb/serial/io_usbvend.h
@@ -594,7 +594,7 @@ struct edge_boot_descriptor {
struct ti_i2c_desc {
__u8 Type; // Type of descriptor
- __u16 Size; // Size of data only not including header
+ __le16 Size; // Size of data only not including header
__u8 CheckSum; // Checksum (8 bit sum of data only)
__u8 Data[0]; // Data starts here
} __attribute__((packed));
--
1.8.3.2
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