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[Qemu-devel] [PATCH 4/4] usb-linux: allow "compatible" high speed device
From: |
Hans de Goede |
Subject: |
[Qemu-devel] [PATCH 4/4] usb-linux: allow "compatible" high speed devices to connect at fullspeed |
Date: |
Tue, 31 May 2011 11:39:43 +0200 |
Some usb2 highspeed devices, like usb-msd devices, work fine when redirected
to a usb1 virtual controller. Allow this to avoid the new speedhecks causing
regressions for users who do not enable the new experimental ehci code.
---
usb-linux.c | 39 +++++++++++++++++++++++++++++++++++++++
1 files changed, 39 insertions(+), 0 deletions(-)
diff --git a/usb-linux.c b/usb-linux.c
index 71e5f4d..187e6ae 100644
--- a/usb-linux.c
+++ b/usb-linux.c
@@ -1062,6 +1062,42 @@ static int usb_linux_update_endp_table(USBHostDevice *s)
return 0;
}
+/*
+ * Check if we can safely redirect a usb2 device to a usb1 virtual controller,
+ * this function assumes this is safe, if:
+ * 1) There are no isoc endpoints
+ * 2) There are no interrupt endpoints with a max_packet_size > 64
+ * Note bulk endpoints with a max_packet_size > 64 in theory also are not
+ * usb1 compatible, but in practice this seems to work fine.
+ */
+static int usb_linux_full_speed_compat(USBHostDevice *dev)
+{
+ int i, packet_size;
+
+ /*
+ * usb_linux_update_endp_table only registers info about ep in the current
+ * interface altsettings, so we need to parse the descriptors again.
+ */
+ for (i = 0; (i + 5) < dev->descr_len; i += dev->descr[i]) {
+ if (dev->descr[i + 1] == USB_DT_ENDPOINT) {
+ switch (dev->descr[i + 3] & 0x3) {
+ case 0x00: /* CONTROL */
+ break;
+ case 0x01: /* ISO */
+ return 0;
+ case 0x02: /* BULK */
+ break;
+ case 0x03: /* INTERRUPT */
+ packet_size = dev->descr[i + 4] + (dev->descr[i + 5] << 8);
+ if (packet_size > 64)
+ return 0;
+ break;
+ }
+ }
+ }
+ return 1;
+}
+
static int usb_host_open(USBHostDevice *dev, int bus_num,
int addr, char *port, const char *prod_name, int speed)
{
@@ -1142,6 +1178,9 @@ static int usb_host_open(USBHostDevice *dev, int bus_num,
}
dev->dev.speed = speed;
dev->dev.speedmask = (1 << speed);
+ if (dev->dev.speed == USB_SPEED_HIGH && usb_linux_full_speed_compat(dev)) {
+ dev->dev.speedmask |= USB_SPEED_MASK_FULL;
+ }
printf("husb: grabbed usb device %d.%d\n", bus_num, addr);
--
1.7.5.1