On Tue, 16 Feb 2010, Roel Kluin wrote:
> > I think it'd be better if you hoisted the set'n'test out of the if()
>
> ok, I agree.
>
> > Isn't this the current logic?
> >
> > result = usbat_write_block(us, USBAT_ATA, srb->cmnd, 12,
> > srb->cmnd[0] == GPCMD_BLANK ? 75 : 10, 0);
> > result = result != USB_STOR_TRANSPORT_GOOD;
> > if (result)
> > return result;
>
> Thanks for your comments, Yes that was the current logic, which I thought
> was wrong, but now I think it could also be obscurely written but right:
>
> in drivers/usb/storage/transport.h line 100 note the definitions:
>
> #define USB_STOR_TRANSPORT_GOOD 0 /* Transport good, command good */
> #define USB_STOR_TRANSPORT_FAILED 1 /* Transport good, command failed */
> #define USB_STOR_TRANSPORT_NO_SENSE 2 /* Command failed, no auto-sense */
> #define USB_STOR_TRANSPORT_ERROR 3 /* Transport bad (i.e. device dead) */
>
> With the current logic usbat_hp8200e_transport() returns TRANSPORT_FAILED,
> even if usbat_write_block() returned TRANSPORT_NO_SENSE or TRANSPORT_ERROR.
>
> This could be intended, but then the author chose a very obscure way to write:
>
> if (usbat_write_block(us, USBAT_ATA, srb->cmnd, 12,
> srb->cmnd[0] == GPCMD_BLANK ? 75 : 10, 0) !=
> USB_STOR_TRANSPORT_GOOD)
> return USB_STOR_TRANSPORT_FAILED;
>
> Or was the parenthesis misplaced and should it really be:
>
> result = usbat_write_block(us, USBAT_ATA, srb->cmnd, 12,
> srb->cmnd[0] == GPCMD_BLANK ? 75 : 10, 0);
>
> if (result != USB_STOR_TRANSPORT_GOOD)
> return result;
>
> Maybe someone with the specs/more knowledge of this driver could look into
> this?
It seems pretty clear that your patch was correct and the parens were
misplaced. In usb-storage, transport routines like
usbat_hp8200e_transport() are supposed to return one of the
USB_STOR_TRANSPORT_* codes, not a Boolean value.
I do agree with Joe that it would be better form to separate the
function call and the "if" into two statements, as in your second
version above. Compare with the code a few lines higher:
if ( (result = usbat_multiple_write(us,
registers, data, 7)) != USB_STOR_TRANSPORT_GOOD) {
return result;
}
The meaning is clear, even though this also unnecessarily squeezes a
function call and a test into one statement and includes unneeded {}'s.
Alan Stern
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