Calculate the max packet size correctly. Only bits 0..11 specify the size, bits 11+12 specify the number of (highspeed) microframes the endpoint wants to use.
Signed-off-by: Gerd Hoffmann <kra...@redhat.com> --- usb-linux.c | 19 +++++++++++++++++-- 1 files changed, 17 insertions(+), 2 deletions(-) diff --git a/usb-linux.c b/usb-linux.c index b95c119..5547b02 100644 --- a/usb-linux.c +++ b/usb-linux.c @@ -213,6 +213,22 @@ static int get_iso_buffer_used(USBHostDevice *s, int ep) return s->endp_table[ep - 1].iso_buffer_used; } +static void set_max_packet_size(USBHostDevice *s, int ep, uint8_t *descriptor) +{ + int raw = descriptor[4] + (descriptor[5] << 8); + int size, microframes; + + size = raw & 0x7ff; + switch ((raw >> 11) & 3) { + case 1: microframes = 2; break; + case 2: microframes = 3; break; + default: microframes = 1; break; + } + DPRINTF("husb: max packet size: 0x%x -> %d x %d\n", + raw, microframes, size); + s->endp_table[ep - 1].max_packet_size = size * microframes; +} + static int get_max_packet_size(USBHostDevice *s, int ep) { return s->endp_table[ep - 1].max_packet_size; @@ -1008,8 +1024,7 @@ static int usb_linux_update_endp_table(USBHostDevice *s) break; case 0x01: type = USBDEVFS_URB_TYPE_ISO; - s->endp_table[(devep & 0xf) - 1].max_packet_size = - descriptors[i + 4] + (descriptors[i + 5] << 8); + set_max_packet_size(s, (devep & 0xf), descriptors + i); break; case 0x02: type = USBDEVFS_URB_TYPE_BULK; -- 1.7.1