On 8/11/20 9:03 AM, Alan Stern wrote:
> On Tue, Aug 11, 2020 at 08:15:05AM -0700, trix@xxxxxxxxxx wrote:
>> From: Tom Rix <trix@xxxxxxxxxx>
>>
>> clang static analysis reports this representative problem
>>
>> realtek_cr.c:639:3: warning: The left expression of the compound
>> assignment is an uninitialized value. The computed value will
>> also be garbage
>> SET_BIT(value, 2);
>> ^~~~~~~~~~~~~~~~~
>>
>> value is set by a successful call to rts51x_read_mem()
>>
>> retval = rts51x_read_mem(us, 0xFE77, &value, 1);
>> if (retval < 0)
>> return -EIO;
>>
>> A successful call to rts51x_read_mem returns 0, failure can
>> return positive and negative values. This check is wrong
>> for a number of functions. Fix the retval check.
>>
>> Fixes: 065e60964e29 ("ums_realtek: do not use stack memory for DMA")
>> Signed-off-by: Tom Rix <trix@xxxxxxxxxx>
>> ---
>> drivers/usb/storage/realtek_cr.c | 36 ++++++++++++++++----------------
>> 1 file changed, 18 insertions(+), 18 deletions(-)
>>
>> diff --git a/drivers/usb/storage/realtek_cr.c b/drivers/usb/storage/realtek_cr.c
>> index 3789698d9d3c..b983753e2368 100644
>> --- a/drivers/usb/storage/realtek_cr.c
>> +++ b/drivers/usb/storage/realtek_cr.c
>> @@ -481,16 +481,16 @@ static int enable_oscillator(struct us_data *us)
>> u8 value;
>>
>> retval = rts51x_read_mem(us, 0xFE77, &value, 1);
>> - if (retval < 0)
>> + if (retval != STATUS_SUCCESS)
>> return -EIO;
> Instead of changing all these call sites, wouldn't it be a lot easier
> just to change rts51x_read_mem() to make it always return a negative
> value (such as -EIO) when there's an error?
>
> Alan Stern
I thought about that but there was already existing (retval != STATUS_SUCCESS) checks for these calls.
Tom
>
