RE: About TRB_TO_EP_INDEX() macro using

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



> On Mon, Aug 05, 2013 at 08:07:25AM +0000, Du, ChangbinX wrote:
> > Recently when I check xHCI code, find that some functions try to get EP index
> > from a Command Completion Event TRB via TRB_TO_EP_INDEX() macro.
> >
> > This is totally wrong. The macro definition is:
> >
> > 	#define TRB_TO_EP_INDEX(p)		((((p) & (0x1f << 16)) >> 16) - 1)
> >
> > TRB_TO_EP_INDEX only applies to Transfer Event TRB. But for Command
> > Completion Event TRB, there is no Endpoint ID field. So, we cannot directly
> > get EP index from these TRBs, but we can find it by the TRB Pointer.
> >
> > Here list two functions for you to check:
> > 	handle_stopped_endpoint()
> > 	handle_reset_ep_completion()
> 
> Care to send a patch showing how you would change this if it is
> incorrect?
> 
> thanks,
> 
> greg k-h
> --

Hello, Greg k-h. I am not very sure about this issue. If this is true, kernel will panic when 
invoking above functions. I want someone help to confirm if I miss something. If it's really 
a bug, I will work out a patch to fix it.
--
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




[Index of Archives]     [Linux Media]     [Linux Input]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [Old Linux USB Devel Archive]

  Powered by Linux