Hi _again_
I've got it this time :-)
On Monday 21 Feb 2005 22:24, Chris Clayton wrote:
> On Sun, 20 Feb 2005 08:39:51 +0000
> > My word, I've put some hours into this, but I now have a 2.6.10 kernel
> > with which the built-in USB port on my Compaq Armada 7400 works. So far
> > that is, I want to do a bit more work on fine tuning the duration of the
> > delays I have added to host/ohci-q.c::finish_unlinks() - 5 millseconds
> > only works some of the time, 10 milliseconds seems to work all of the
> > time.
>
> Mmm, spoke a bit too soon. Trying to find the sweet spot between 5 and 10
> millisecs, I'm currently at ...... 20 milliseconds. I had done some testing
> yesterday, copying 5-6MB files to and from compact flash and over the
> wireless network, and all was OK. However, tonight I've been copying a
> kernel tarball around and getting timeouts again, so it looks like I've got
> some more work to do. Sorry for the noise :)
>
The problem was that I had (foolishly) missed a couple of places where I
needed to insert a delay. The good news is that having added the two
additional delays, the duration of each of them (the new ones and the
originals) now needs to be only 1 millisecond. Furthermore, the first delay
we introduced (in core/message.c::usb_internal_control_msg() appears to be no
longer needed.
I've tried the fix with both 2.6.10 and 2.6.11-rc4 and it works fine. By that
I mean that I can repeatedly copy a kernel tarball to/from compact flash and
between
machines on my wireless network without error. A USB mouse works perfectly
too. All this is with the devices connected directly to the usb port or via
an unpowered hub. Without the patch, I can't even connect the hub
successfully.
The patch for 2.6.11-rc4 follows.
In case you think it is suitable for permananent inclusion in the kernel:
Signed off by: Chris Clayton <[EMAIL PROTECTED]>
--- linux-2.6.11-rc4/drivers/usb/host/ohci-q.c.orig 2005-02-13
03:07:40.000000000 +0000
+++ linux-2.6.11-rc4/drivers/usb/host/ohci-q.c 2005-02-23 21:16:16.000000000
+0000
@@ -1018,6 +1018,8 @@
if (ohci->ed_controltail) {
command |= OHCI_CLF;
+ /* give old and slow silicon a little time */
+ mdelay(1);
if (!(ohci->hc_control & OHCI_CTRL_CLE)) {
control |= OHCI_CTRL_CLE;
ohci_writel (ohci, 0,
@@ -1026,6 +1028,8 @@
}
if (ohci->ed_bulktail) {
command |= OHCI_BLF;
+ /* give old and slow silicon a little time */
+ mdelay(1);
if (!(ohci->hc_control & OHCI_CTRL_BLE)) {
control |= OHCI_CTRL_BLE;
ohci_writel (ohci, 0,
@@ -1036,12 +1040,17 @@
/* CLE/BLE to enable, CLF/BLF to (maybe) kickstart */
if (control) {
ohci->hc_control |= control;
+ /* give old and slow silicon a little time */
+ mdelay(1);
ohci_writel (ohci, ohci->hc_control,
&ohci->regs->control);
}
- if (command)
+ if (command) {
+ /* give old and slow silicon a little time */
+ mdelay(1);
ohci_writel (ohci, command, &ohci->regs->cmdstatus);
- }
+ }
+ }
}
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