| Message ID | 20230425120810.5365-1-wlodzimierz.lipert@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | usb: libcomposite: prevent duplicate bEndpointAddress by usb_ep_autoconfig_ss. | expand |
On Tue, Apr 25, 2023 at 02:08:10PM +0200, Wlodzimierz Lipert wrote: > usb_ep_autoconfig_ss tries to use endpoint name or internal counters to generate > bEndpointAddress - this leads to duplicate addresses. Fix is simple - > use only internal counter and dont rely on ep naming scheme. I don't think that's the right fix. On some UDCs the endpoint number really is determined by the hardware; you can't change it. That's why the number is part of the endpoint's name. The proper fix would be to check, when using the internal counter, whether a particular endpoint number is already reserved, and skip over it if it is. Alan Stern PS: usb_ep_autoconfig_ss() isn't part of libcomposite. It's available for use by any gadget, whether that gadget uses the composite framework or not. > > Signed-off-by: Wlodzimierz Lipert <wlodzimierz.lipert@gmail.com> > --- > drivers/usb/gadget/epautoconf.c | 5 +---- > 1 file changed, 1 insertion(+), 4 deletions(-) > > diff --git a/drivers/usb/gadget/epautoconf.c b/drivers/usb/gadget/epautoconf.c > index 1eb4fa2e623f..40adf09079ed 100644 > --- a/drivers/usb/gadget/epautoconf.c > +++ b/drivers/usb/gadget/epautoconf.c > @@ -93,10 +93,7 @@ struct usb_ep *usb_ep_autoconfig_ss( > > /* report address */ > desc->bEndpointAddress &= USB_DIR_IN; > - if (isdigit(ep->name[2])) { > - u8 num = simple_strtoul(&ep->name[2], NULL, 10); > - desc->bEndpointAddress |= num; > - } else if (desc->bEndpointAddress & USB_DIR_IN) { > + if (desc->bEndpointAddress & USB_DIR_IN) { > if (++gadget->in_epnum > 15) > return NULL; > desc->bEndpointAddress = USB_DIR_IN | gadget->in_epnum; > -- > 2.39.2 >
Hi Alan, What do you think if we keep not counter but bitmap in u32 (32 is max amount of HW endpoints anyway) ? On Tue, Apr 25, 2023 at 4:32 PM Alan Stern <stern@rowland.harvard.edu> wrote: > > On Tue, Apr 25, 2023 at 02:08:10PM +0200, Wlodzimierz Lipert wrote: > > usb_ep_autoconfig_ss tries to use endpoint name or internal counters to generate > > bEndpointAddress - this leads to duplicate addresses. Fix is simple - > > use only internal counter and dont rely on ep naming scheme. > > I don't think that's the right fix. On some UDCs the endpoint number > really is determined by the hardware; you can't change it. That's why > the number is part of the endpoint's name. > > The proper fix would be to check, when using the internal counter, > whether a particular endpoint number is already reserved, and skip over > it if it is. > > Alan Stern > > PS: usb_ep_autoconfig_ss() isn't part of libcomposite. It's available > for use by any gadget, whether that gadget uses the composite framework > or not. > > > > > Signed-off-by: Wlodzimierz Lipert <wlodzimierz.lipert@gmail.com> > > --- > > drivers/usb/gadget/epautoconf.c | 5 +---- > > 1 file changed, 1 insertion(+), 4 deletions(-) > > > > diff --git a/drivers/usb/gadget/epautoconf.c b/drivers/usb/gadget/epautoconf.c > > index 1eb4fa2e623f..40adf09079ed 100644 > > --- a/drivers/usb/gadget/epautoconf.c > > +++ b/drivers/usb/gadget/epautoconf.c > > @@ -93,10 +93,7 @@ struct usb_ep *usb_ep_autoconfig_ss( > > > > /* report address */ > > desc->bEndpointAddress &= USB_DIR_IN; > > - if (isdigit(ep->name[2])) { > > - u8 num = simple_strtoul(&ep->name[2], NULL, 10); > > - desc->bEndpointAddress |= num; > > - } else if (desc->bEndpointAddress & USB_DIR_IN) { > > + if (desc->bEndpointAddress & USB_DIR_IN) { > > if (++gadget->in_epnum > 15) > > return NULL; > > desc->bEndpointAddress = USB_DIR_IN | gadget->in_epnum; > > -- > > 2.39.2 > >
On Tue, Apr 25, 2023 at 04:44:50PM +0200, Wlodzimierz Lipert wrote: > Hi Alan, > > What do you think if we keep not counter but bitmap in u32 (32 is max > amount of HW endpoints anyway) ? That sounds like a good idea. Alan Stern > On Tue, Apr 25, 2023 at 4:32 PM Alan Stern <stern@rowland.harvard.edu> wrote: > > > > On Tue, Apr 25, 2023 at 02:08:10PM +0200, Wlodzimierz Lipert wrote: > > > usb_ep_autoconfig_ss tries to use endpoint name or internal counters to generate > > > bEndpointAddress - this leads to duplicate addresses. Fix is simple - > > > use only internal counter and dont rely on ep naming scheme. > > > > I don't think that's the right fix. On some UDCs the endpoint number > > really is determined by the hardware; you can't change it. That's why > > the number is part of the endpoint's name. > > > > The proper fix would be to check, when using the internal counter, > > whether a particular endpoint number is already reserved, and skip over > > it if it is. > > > > Alan Stern > > > > PS: usb_ep_autoconfig_ss() isn't part of libcomposite. It's available > > for use by any gadget, whether that gadget uses the composite framework > > or not. > > > > > > > > Signed-off-by: Wlodzimierz Lipert <wlodzimierz.lipert@gmail.com> > > > --- > > > drivers/usb/gadget/epautoconf.c | 5 +---- > > > 1 file changed, 1 insertion(+), 4 deletions(-) > > > > > > diff --git a/drivers/usb/gadget/epautoconf.c b/drivers/usb/gadget/epautoconf.c > > > index 1eb4fa2e623f..40adf09079ed 100644 > > > --- a/drivers/usb/gadget/epautoconf.c > > > +++ b/drivers/usb/gadget/epautoconf.c > > > @@ -93,10 +93,7 @@ struct usb_ep *usb_ep_autoconfig_ss( > > > > > > /* report address */ > > > desc->bEndpointAddress &= USB_DIR_IN; > > > - if (isdigit(ep->name[2])) { > > > - u8 num = simple_strtoul(&ep->name[2], NULL, 10); > > > - desc->bEndpointAddress |= num; > > > - } else if (desc->bEndpointAddress & USB_DIR_IN) { > > > + if (desc->bEndpointAddress & USB_DIR_IN) { > > > if (++gadget->in_epnum > 15) > > > return NULL; > > > desc->bEndpointAddress = USB_DIR_IN | gadget->in_epnum; > > > -- > > > 2.39.2 > > > > > > > -- > BR/Pozdrawiam. Wlodzimierz Lipert
diff --git a/drivers/usb/gadget/epautoconf.c b/drivers/usb/gadget/epautoconf.c index 1eb4fa2e623f..40adf09079ed 100644 --- a/drivers/usb/gadget/epautoconf.c +++ b/drivers/usb/gadget/epautoconf.c @@ -93,10 +93,7 @@ struct usb_ep *usb_ep_autoconfig_ss( /* report address */ desc->bEndpointAddress &= USB_DIR_IN; - if (isdigit(ep->name[2])) { - u8 num = simple_strtoul(&ep->name[2], NULL, 10); - desc->bEndpointAddress |= num; - } else if (desc->bEndpointAddress & USB_DIR_IN) { + if (desc->bEndpointAddress & USB_DIR_IN) { if (++gadget->in_epnum > 15) return NULL; desc->bEndpointAddress = USB_DIR_IN | gadget->in_epnum;
usb_ep_autoconfig_ss tries to use endpoint name or internal counters to generate bEndpointAddress - this leads to duplicate addresses. Fix is simple - use only internal counter and dont rely on ep naming scheme. Signed-off-by: Wlodzimierz Lipert <wlodzimierz.lipert@gmail.com> --- drivers/usb/gadget/epautoconf.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-)