From 0b377169b18d702d980d526578d8515900ca6eb1 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Thu, 19 Apr 2012 13:36:40 +0200 Subject: [PATCH] usb-host: fix zero-length packets usb-host optimizes away zero-length packets by not entering the processing loop at all. Which isn't correct, we should submit a zero-length urb to the host devicein that case. This patch makes sure we run the processing loop at least once. Signed-off-by: Gerd Hoffmann --- hw/usb/host-linux.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/hw/usb/host-linux.c b/hw/usb/host-linux.c index c3684c8f92..048f8ffa8b 100644 --- a/hw/usb/host-linux.c +++ b/hw/usb/host-linux.c @@ -887,8 +887,8 @@ static int usb_host_handle_data(USBDevice *dev, USBPacket *p) prem = 0; pbuf = NULL; rem = p->iov.size; - while (rem) { - if (prem == 0) { + do { + if (prem == 0 && rem > 0) { assert(v < p->iov.niov); prem = p->iov.iov[v].iov_len; pbuf = p->iov.iov[v].iov_base; @@ -938,7 +938,7 @@ static int usb_host_handle_data(USBDevice *dev, USBPacket *p) return USB_RET_STALL; } } - } + } while (rem > 0); return USB_RET_ASYNC; } -- GitLab