uhci: fix bandwidth management

uhci_process_frame() can be invoked multiple times per frame, so
accounting usb bandwith in a local variable doesn't fly, use a variable
in UHCIState instead.  Also check the limit more frequently.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This commit is contained in:
Gerd Hoffmann 2012-05-11 09:18:05 +02:00
parent 349417004a
commit 4aed20e2d7
2 changed files with 13 additions and 11 deletions

View File

@ -131,6 +131,7 @@ struct UHCIState {
uint8_t status2; /* bit 0 and 1 are used to generate UHCI_STS_USBINT */
int64_t expire_time;
QEMUTimer *frame_timer;
uint32_t frame_bytes;
UHCIPort ports[NB_PORTS];
/* Interrupts that should be raised at the end of the current frame. */
@ -985,7 +986,7 @@ static void uhci_fill_queue(UHCIState *s, UHCI_TD *td)
static void uhci_process_frame(UHCIState *s)
{
uint32_t frame_addr, link, old_td_ctrl, val, int_mask;
uint32_t curr_qh, td_count = 0, bytes_count = 0;
uint32_t curr_qh, td_count = 0;
int cnt, ret;
UHCI_TD td;
UHCI_QH qh;
@ -1002,6 +1003,12 @@ static void uhci_process_frame(UHCIState *s)
qhdb_reset(&qhdb);
for (cnt = FRAME_MAX_LOOPS; is_valid(link) && cnt; cnt--) {
if (s->frame_bytes >= 1280) {
/* We've reached the usb 1.1 bandwidth, which is
1280 bytes/frame, stop processing */
trace_usb_uhci_frame_stop_bandwidth();
break;
}
if (is_qh(link)) {
/* QH */
trace_usb_uhci_qh_load(link & ~0xf);
@ -1011,18 +1018,12 @@ static void uhci_process_frame(UHCIState *s)
* We're going in circles. Which is not a bug because
* HCD is allowed to do that as part of the BW management.
*
* Stop processing here if
* (a) no transaction has been done since we've been
* here last time, or
* (b) we've reached the usb 1.1 bandwidth, which is
* 1280 bytes/frame.
* Stop processing here if no transaction has been done
* since we've been here last time.
*/
if (td_count == 0) {
trace_usb_uhci_frame_loop_stop_idle();
break;
} else if (bytes_count >= 1280) {
trace_usb_uhci_frame_loop_stop_bandwidth();
break;
} else {
trace_usb_uhci_frame_loop_continue();
td_count = 0;
@ -1085,7 +1086,7 @@ static void uhci_process_frame(UHCIState *s)
trace_usb_uhci_td_complete(curr_qh & ~0xf, link & ~0xf);
link = td.link;
td_count++;
bytes_count += (td.ctrl & 0x7ff) + 1;
s->frame_bytes += (td.ctrl & 0x7ff) + 1;
if (curr_qh) {
/* update QH element link */
@ -1118,6 +1119,7 @@ static void uhci_frame_timer(void *opaque)
/* prepare the timer for the next frame */
s->expire_time += (get_ticks_per_sec() / FRAME_TIMER_FREQ);
s->frame_bytes = 0;
if (!(s->cmd & UHCI_CMD_RS)) {
/* Full stop */

View File

@ -263,8 +263,8 @@ usb_uhci_reset(void) "=== RESET ==="
usb_uhci_schedule_start(void) ""
usb_uhci_schedule_stop(void) ""
usb_uhci_frame_start(uint32_t num) "nr %d"
usb_uhci_frame_stop_bandwidth(void) ""
usb_uhci_frame_loop_stop_idle(void) ""
usb_uhci_frame_loop_stop_bandwidth(void) ""
usb_uhci_frame_loop_continue(void) ""
usb_uhci_mmio_readw(uint32_t addr, uint32_t val) "addr %04x, ret 0x04%x"
usb_uhci_mmio_writew(uint32_t addr, uint32_t val) "addr %04x, val 0x04%x"