Patchwork [v4,28/32] usb storage: handle long responses

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Submitter Gerd Hoffmann
Date Jan. 12, 2011, 11:20 a.m.
Message ID <1294831214-4499-29-git-send-email-kraxel@redhat.com>
Download mbox | patch
Permalink /patch/78579/
State New
Headers show

Comments

Gerd Hoffmann - Jan. 12, 2011, 11:20 a.m.
The scsi layer may return us more data than the guests wants to have.
Handle this by just ignoring the extra bytes and calling the
{read,write}_data callback to finish the request.

Seen happening in real life with some extended inquiry command.
With this patch applied the linux kernel stops reseting the device
once at boot.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 hw/usb-msd.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

Patch

diff --git a/hw/usb-msd.c b/hw/usb-msd.c
index 28c12dd..729d96c 100644
--- a/hw/usb-msd.c
+++ b/hw/usb-msd.c
@@ -187,7 +187,7 @@  static void usb_msd_copy_data(MSDState *s)
     s->usb_buf += len;
     s->scsi_buf += len;
     s->data_len -= len;
-    if (s->scsi_len == 0) {
+    if (s->scsi_len == 0 || s->data_len == 0) {
         if (s->mode == USB_MSDM_DATAIN) {
             s->scsi_dev->info->read_data(s->scsi_dev, s->tag);
         } else if (s->mode == USB_MSDM_DATAOUT) {
@@ -434,7 +434,7 @@  static int usb_msd_handle_data(USBDevice *dev, USBPacket *p)
             break;
 
         case USB_MSDM_DATAIN:
-            DPRINTF("Data in %d/%d\n", len, s->data_len);
+            DPRINTF("Data in %d/%d, scsi_len %d\n", len, s->data_len, s->scsi_len);
             if (len > s->data_len)
                 len = s->data_len;
             s->usb_buf = data;