Messages in this thread |  | | | From | Linus Torvalds <> | | Date | Mon, 2 Jul 2012 11:52:23 -0700 | | Subject | Re: [ 38/48] SCSI & usb-storage: add try_rc_10_first flag |
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On Mon, Jul 2, 2012 at 12:10 AM, Hans de Goede <hdegoede@redhat.com> wrote: > > So since 3.2 already tries READ_CAPACITY(10) first, this patch is > not needed. It does not harm either, and if the scsi level reporting > change ever finds its way into 3.2 stable (which it should not > IMHO), then this patch will be needed.
Yeah, it should definitely not make it into stable. In fact, I'd rather remove it from mainline too. The whole idea to do READ_CAPACITY_16 by default was moronic.
James? Why does the SCSI subsystem always do these idiotic defaults? We *know* that devices are buggy. Sure, USB storage tends to be buggier than most, but the whole idea of "let's use the new way of reporting that gets almost no testing" is just wrong.
I don't think the USB layer should have needed to work around this. I don't think there should be a "try_10b" flag at all. I think the SCSI code should just *never* do the 16b version unless it has done the 10b version first and determined that the size doesn't fit.
And the code already had that logic got the read_10b case. The whole logic to do 16b by default was crap. It *used* to at least only do it for disks that were marked as having "protection", now it wants to do it for anything that should be able to handle it. Which is bogus. The whole "let's assume devices get it right" mindset is broken.
The mindset should be "let's assume devices are buggy, and be careful".
Linus
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