• Marcin Slusarz's avatar
    usbtest: comment on why this code "expects" negative and positive errnos · 6def7553
    Marcin Slusarz authored
    
    
    On Mon, May 12, 2008 at 01:02:22AM -0700, David Brownell wrote:
    > On Sunday 11 May 2008, Marcin Slusarz wrote:
    > > 
    > > test_ctrl_queue expects (?) positive and negative errnos.
    > > what is going on here?
    > 
    > The sign is just a way to flag something:
    > 
    >                 /* some faults are allowed, not required */
    > 
    > The negative ones are required.  Positive codes are optional,
    > in the sense that, depending on how the peripheral happens
    > to be implemented, they won't necessarily be triggered.
    > 
    > For example, the test to fetch a device qualifier desriptor
    > must succeed if the device is running at high speed.  So that
    > test is marked as negative.  But when it's full speed, it
    > could legitimately fail; marked as positive.  And so on for
    > other tests.
    > 
    > Look at how the codes are *interpreted* to see it work.
    
    Lets document it.
    
    Based on comment from David Brownell <david-b@pacbell.net>.
    Signed-off-by: default avatarMarcin Slusarz <marcin.slusarz@gmail.com>
    Cc: David Brownell <david-b@pacbell.net>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
    6def7553
usbtest.c 57.3 KB