On Thu, Dec 09, 2010 at 04:11:55PM -0800, Sarah Sharp wrote: > On Thu, Dec 09, 2010 at 02:54:19PM -0800, Luben Tuikov wrote: > > --- On Thu, 12/9/10, Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx> wrote: > > > -0800, Luben Tuikov wrote: > > > > Signed-off-by: Luben Tuikov <ltuikov@xxxxxxxxx> > > > > --- > > > > The long story is that we see some host > > > controllers misreport their > > > > PSA as they solved 2^v = streams, instead of > > > 2^(v+1) = streams. Thus > > > > They report that they support 32 streams when in > > > fact they support 16. > > > > When the device attempts to return status for > > > stream > 15, the host > > > > says ACK(NumP=0), the device goes in flow > > > control, blah, blah, this > > > > module parameter allows you to set a max cap on > > > the number of streams > > > > the driver will ask XHCI HCD to allocate. > > > > > > If this is an issue with a host then the work-around should > > > be in the > > > xHCI driver instead. It should be based on the > > > vendor/device ID of the > > > offending host instead of being a module parameter in the > > > UAS driver. > > > The only people who benefit from this patch are the people > > > "in the know" > > > about which hosts are buggy, not normal Linux users. > > > > The OS might want to limit the number of streams for reasons other > > than a buggy HC. So this module parameter add flexibility other than > > making a buggy HC work. > > Ok, that's fine, but my comments still stand about fixing this > particular bug in the xHCI driver, rather than in the UAS driver. I agree. Also, a module parameter will not work when your driver is connecting to different xHCI devices in the same system. Please never add module parameters anymore, there is usually never a need for them at all. thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
