OpenE2K/qemu-e2k
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usb-redir: Try to keep our buffer size near the target size

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Before this patch we would allow the (iso) buffer to grow unlimited
(and it would under certain circumstances) leading to way too high
latencies for iso data streams.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This commit is contained in:
Hans de Goede 2012-01-10 14:13:07 +01:00 committed by Gerd Hoffmann
parent e153788479
commit 81fd7b7495
1 changed files with 27 additions and 3 deletions
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30
usb-redir.c
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@ -61,6 +61,7 @@ struct endp_data {
uint8_t interrupt_started;
uint8_t interrupt_error;
uint8_t bufpq_prefilled;
uint8_t bufpq_dropping_packets;
QTAILQ_HEAD(, buf_packet) bufpq;
int bufpq_size;
int bufpq_target_size;
@ -290,16 +291,34 @@ static void usbredir_cancel_packet(USBDevice *udev, USBPacket *p)
}
}
static struct buf_packet *bufp_alloc(USBRedirDevice *dev,
static void bufp_alloc(USBRedirDevice *dev,
uint8_t *data, int len, int status, uint8_t ep)
{
struct buf_packet *bufp = g_malloc(sizeof(struct buf_packet));
struct buf_packet *bufp;
if (!dev->endpoint[EP2I(ep)].bufpq_dropping_packets &&
dev->endpoint[EP2I(ep)].bufpq_size >
2 * dev->endpoint[EP2I(ep)].bufpq_target_size) {
DPRINTF("bufpq overflow, dropping packets ep %02X\n", ep);
dev->endpoint[EP2I(ep)].bufpq_dropping_packets = 1;
}
/* Since we're interupting the stream anyways, drop enough packets to get
back to our target buffer size */
if (dev->endpoint[EP2I(ep)].bufpq_dropping_packets) {
if (dev->endpoint[EP2I(ep)].bufpq_size >
dev->endpoint[EP2I(ep)].bufpq_target_size) {
free(data);
return;
}
dev->endpoint[EP2I(ep)].bufpq_dropping_packets = 0;
}
bufp = g_malloc(sizeof(struct buf_packet));
bufp->data = data;
bufp->len = len;
bufp->status = status;
QTAILQ_INSERT_TAIL(&dev->endpoint[EP2I(ep)].bufpq, bufp, next);
dev->endpoint[EP2I(ep)].bufpq_size++;
return bufp;
}
static void bufp_free(USBRedirDevice *dev, struct buf_packet *bufp,
@ -379,6 +398,7 @@ static int usbredir_handle_iso_data(USBRedirDevice *dev, USBPacket *p,
DPRINTF("iso stream started ep %02X\n", ep);
dev->endpoint[EP2I(ep)].iso_started = 1;
dev->endpoint[EP2I(ep)].bufpq_prefilled = 0;
dev->endpoint[EP2I(ep)].bufpq_dropping_packets = 0;
}
if (ep & USB_DIR_IN) {
@ -505,6 +525,10 @@ static int usbredir_handle_interrupt_data(USBRedirDevice *dev,
usbredirparser_do_write(dev->parser);
DPRINTF("interrupt recv started ep %02X\n", ep);
dev->endpoint[EP2I(ep)].interrupt_started = 1;
/* We don't really want to drop interrupt packets ever, but
having some upper limit to how much we buffer is good. */
dev->endpoint[EP2I(ep)].bufpq_target_size = 1000;
dev->endpoint[EP2I(ep)].bufpq_dropping_packets = 0;
}
intp = QTAILQ_FIRST(&dev->endpoint[EP2I(ep)].bufpq);