Hi Stefan, On Fri, Jul 17, 2020 at 6:08 PM Stefan Roese <[email protected]> wrote: > > On 17.07.20 07:33, Bin Meng wrote: > > Hi Stefan, > > > > On Thu, Jul 2, 2020 at 4:47 PM Stefan Roese <[email protected]> wrote: > >> > >> These values are already swapped to CPU endianess, so swapping them > > > > Can you please add more details as to when these values are swapped? I > > assume this is inside usb_select_config() which is called before this > > function is called? > > Yes. Its swapped exactly here: > > int usb_select_config(struct usb_device *dev) > { > unsigned char *tmpbuf = NULL; > int err; > > err = get_descriptor_len(dev, USB_DT_DEVICE_SIZE, USB_DT_DEVICE_SIZE); > if (err) > return err; > > /* correct le values */ > le16_to_cpus(&dev->descriptor.bcdUSB); > le16_to_cpus(&dev->descriptor.idVendor); > le16_to_cpus(&dev->descriptor.idProduct); > le16_to_cpus(&dev->descriptor.bcdDevice); > > > But I wonder how this code ever worked on ARM/x86? > > On ARM/x86, the little-endian swapping is a no-op. So it doesn't matter > if you swap once or twice or... ;) >
Ah, yes! I misread this as an unconditional swap ... > >> again is a bug. Let's remove the swap here instead. > >> > >> Signed-off-by: Stefan Roese <[email protected]> > >> Cc: Bin Meng <[email protected]> > >> Cc: Marek Vasut <[email protected]> > >> --- > >> > >> drivers/usb/host/usb-uclass.c | 8 ++++---- > >> 1 file changed, 4 insertions(+), 4 deletions(-) > >> Regards, Bin
