[U-Boot] [PATCH] fs: fat: fix wrong casting to unsigned value of sect_to_cluster()

[Seung-Woo Kim]

Hello,

On 2018년 06월 05일 06:58, Tom Rini wrote:
> On Mon, Jun 04, 2018 at 08:45:54PM +0900, Seung-Woo Kim wrote:
> 
>> After the commit 265edc03d5a1 ("fs/fat: Clean up open-coded sector
>> <-> cluster conversions"), it is hung up writing new file to FAT16
>> disk with more than 19 files in armv7. It is because result value
>> of sect_to_cluster() is not proper by casting from signed value to
>> unsigned value. Fix the wrong casting of sect_to_cluster().
>>
>> Reported-by: Jaehoon Chung <jh80.chung at samsung.com>
>> Signed-off-by: Seung-Woo Kim <sw0312.kim at samsung.com>
>> ---
>>  include/fat.h |    2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> Can you please also update test/fs-test.sh with a testcase for this?
> Thanks!
> 

The simple test way is doing fat-write more than 20 files with long file
name to FAT16 image.

For example, in my armv7 odroid-xu3 target with empty fat16 root,
writing like following:

fatwrite mmc 0 13000000 01000000000000000000 4
fatwrite mmc 0 13000000 02000000000000000000 4
..
fatwrite mmc 0 13000000 21000000000000000000 4

and then 22th writing was failed like following:

ODROID-XU3 # fatwrite mmc 0 13000000 22000000000000000000 4
writing 22000000000000000000
Error: Invalid FAT entry: 0x3ffffffa
Invalid FAT entry
Error: Invalid FAT entry: 0x3ffffffa

I tested same thing with sandbox u-boot on x86, there was no error like
armv7. So, I am not sure it is helpful to add testcase for this.

Best Regards,
- Seung-Woo Kim


-- 
Seung-Woo Kim
Samsung Research
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