From patchwork Fri Aug 17 09:39:16 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [2/3] usb: controllers do not need to check for babble themselves Date: Thu, 16 Aug 2012 23:39:16 -0000 From: Hans de Goede X-Patchwork-Id: 178178 Message-Id: <1345196357-6076-2-git-send-email-hdegoede@redhat.com> To: Gerd Hoffmann Cc: Hans de Goede , qemu-devel@nongnu.org If an (emulated) usb-device tries to write more data to a packet then its iov len, this will trigger an assert in usb_packet_copy(), and if a driver somehow circumvents that check and writes more data to the iov then there is space, we have a much bigger problem then not correctly reporting babble to the guest. In practice babble will only happen with (real) redirected devices, and there both the usb-host os and the qemu usb-device code already check for it. Signed-off-by: Hans de Goede --- hw/usb/hcd-ehci.c | 4 ---- hw/usb/hcd-uhci.c | 5 ----- 2 files changed, 9 deletions(-) diff --git a/hw/usb/hcd-ehci.c b/hw/usb/hcd-ehci.c index a6b8527..4750175 100644 --- a/hw/usb/hcd-ehci.c +++ b/hw/usb/hcd-ehci.c @@ -1460,10 +1460,6 @@ static void ehci_execute_complete(EHCIQueue *q) assert(0); break; } - } else if ((p->usb_status > p->tbytes) && (p->pid == USB_TOKEN_IN)) { - p->usb_status = USB_RET_BABBLE; - q->qh.token |= (QTD_TOKEN_HALT | QTD_TOKEN_BABBLE); - ehci_raise_irq(q->ehci, USBSTS_ERRINT); } else { // TODO check 4.12 for splits diff --git a/hw/usb/hcd-uhci.c b/hw/usb/hcd-uhci.c index 8987734..4e43d20 100644 --- a/hw/usb/hcd-uhci.c +++ b/hw/usb/hcd-uhci.c @@ -729,11 +729,6 @@ static int uhci_complete_td(UHCIState *s, UHCI_TD *td, UHCIAsync *async, uint32_ *int_mask |= 0x01; if (pid == USB_TOKEN_IN) { - if (len > max_len) { - ret = USB_RET_BABBLE; - goto out; - } - if ((td->ctrl & TD_CTRL_SPD) && len < max_len) { *int_mask |= 0x02; /* short packet: do not update QH */