> -----Original Message----- > From: Elric Fu [mailto:elricfu1@xxxxxxxxx] > Sent: Thursday, March 29, 2012 5:34 PM > To: Xu, Andiry > Cc: Sarah Sharp; linux-usb@xxxxxxxxxxxxxxx > Subject: Re: [RFT v2] xHCI: cancel command queued in the command ring > > 2012/3/29 Xu, Andiry <Andiry.Xu@xxxxxxx>: > >> -----Original Message----- > >> From: Elric Fu [mailto:elricfu1@xxxxxxxxx] > >> Sent: Thursday, March 29, 2012 5:13 PM > >> To: Sarah Sharp > >> Cc: Xu, Andiry; Elric Fu; linux-usb@xxxxxxxxxxxxxxx > >> Subject: [RFT v2] xHCI: cancel command queued in the command ring > >> > >> Software have to abort command ring and cancel command > >> when a command is failed or hang. Otherwise, the command > >> ring will hang up and can't handle the others. An example > >> of a command that may hang is the Address Device Command, > >> because waiting for a SET_ADDRESS request to be acknowledged > >> by a USB device is outside of the xHC's ability to control. > >> > >> According to xHCI spec section 4.6.1.1 and section 4.6.1.2, > >> after aborting a command on the command ring, xHC will > >> generate a command completion event with its completion code > >> set to Command Ring Stopped at least. If a command is > >> currently executing at the time of aborting a command, xHC > >> also generate a command completion event with its completion > >> code set to Command Abort. When the command ring is stopped, > >> software may remove, add, or rearrage Command Descriptors. > >> > >> The RFT patch is used to cancel command when the above > >> situation occur. > >> > >> To cancel a command, software will initialize a command > >> descriptor for the cancel command, and add it into a > >> cancel_cmd_list of xhci. When the command ring is stopped, > >> software will find the command trbs described by command > >> descriptors in cancel_cmd_list and modify it to No Op > >> command. If software can't find the matched trbs, we can > >> think it had been finished. > >> > >> Signed-off-by: Elric Fu <elricfu1@xxxxxxxxx> > >> Acked-by: Andiry Xu <Andiry.Xu@xxxxxxx> > > > > I've NOT acked this patch, just provided some comments for > > the last version. Please remove this line. > > Is the RFT's rule different from PATCH? Or I need to add you > in the release patch? > They are all following the same rules. Unless I typed the Acked-by line explicitly in my mail, or I said "You can add my Acked-by after modify this part", you cannot add my Acked-by in your patch. Thanks, Andiry -- 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
