Hi Alan,
I applied the modifications you suggested, this is the output:
[ 110.922009] ehci_hcd 0000:00:0b.1: async off
[ 209.362134] ehci_hcd 0000:00:0b.1: async on
[ 241.794760] ehci_hcd 0000:00:0b.1: alan start cur time 4294908992 last scan 4294878606
[ 241.794774] ehci_hcd 0000:00:0b.1: command 10035 cmd reg 10035 status reg e008
[ 241.794779] ehci_hcd 0000:00:0b.1: async list:
[ 241.794787] ehci_hcd 0000:00:0b.1: qh ffff880149fe7800 hw ffff8800af800000 dma af800000 next ffff880146ce3f80 hw_next af800c62
[ 241.794795] ehci_hcd 0000:00:0b.1: qh ffff880146ce3f80 hw ffff8800af800c60 dma af800c60 next ffff880146ce3780 hw_next af800d22
[ 241.794801] ehci_hcd 0000:00:0b.1: qh ffff880146ce3780 hw ffff8800af800d20 dma af800d20 next ffff880147776680 hw_next af800ae2
[ 241.794808] ehci_hcd 0000:00:0b.1: qh ffff880147776680 hw ffff8800af800ae0 dma af800ae0 next ffff8801478bf380 hw_next af800a22
[ 241.794815] ehci_hcd 0000:00:0b.1: qh ffff8801478bf380 hw ffff8800af800a20 dma af800a20 next ffff88014070da00 hw_next af800f02
[ 241.794821] ehci_hcd 0000:00:0b.1: qh ffff88014070da00 hw ffff8800af800f00 dma af800f00 next ffff8801407d3800 hw_next af800de2
[ 241.794828] ehci_hcd 0000:00:0b.1: qh ffff8801407d3800 hw ffff8800af800de0 dma af800de0 next ffff8801478bfc80 hw_next af800782
[ 241.794834] ehci_hcd 0000:00:0b.1: qh ffff8801478bfc80 hw ffff8800af800780 dma af800780 next ffff88014079e480 hw_next af800ba2
[ 241.794841] ehci_hcd 0000:00:0b.1: qh ffff88014079e480 hw ffff8800af800ba0 dma af800ba0 next ffff8801478bf780 hw_next af8008a2
[ 241.794847] ehci_hcd 0000:00:0b.1: qh ffff8801478bf780 hw ffff8800af8008a0 dma af8008a0 next ffff8801478bfd00 hw_next af800962
[ 241.794854] ehci_hcd 0000:00:0b.1: qh ffff8801478bfd00 hw ffff8800af800960 dma af800960 next (null) hw_next af800002
[ 241.794861] ehci_hcd 0000:00:0b.1: This qh link time 4294878614 enqueue time 4294878614 td token 1f8c80 ov token 0
[ 241.794869] ehci_hcd 0000:00:0b.1: qh ffff8801478bfd00 naf800002 info 4200220e 40000000 qtd af820540
[ 241.794876] ehci_hcd 0000:00:0b.1: overlay td ffff8800af800970 naf820d80 00000001 t00000000 p0=af883a9f
[ 241.794884] ehci_hcd 0000:00:0b.1: dma af820d80 td ffff8800af820d80 naf820960 00000001 t001f8c80 p0=af883a80
[ 241.794892] ehci_hcd 0000:00:0b.1: dummy af820960 td ffff8800af820960 n00000001 00000001 t00000040 p0=00000000
[ 241.805935] ehci_hcd 0000:00:0b.1: giveback urb ffff8801455fa300 actual 0
[ 241.805943] ehci_hcd 0000:00:0b.1: alan end
The first "async off" happened, I guess correctly,
when the hot-plug settled and all the HDDs where
in place as expected.
The "async on" happened as soon as I started to
read 10 HDDs in parallel, I think correctly too.
After few seconds, this time without any "help",
the problem appeared with the log as reported.
I noticed several "async on/off" in dmesg, it
seems to me all were consistent.
bye,
pg
On Sat, Dec 15, 2012 at 03:53:09PM -0500, Alan Stern wrote:
> On Sat, 15 Dec 2012, Piergiorgio Sartor wrote:
>
> > Hi Alan,
> >
> > thanks for the patch, I applied it and tested.
> >
> > I've bad news...
> > Unless I made some mistake (which can always be), I did not
> > see any of the logs of this patch in the output, despite
> > having seen the problem occuring (this time I used "cpuburn"
> > to overload the system).
>
> That's disappointing.
>
> > The only reasonable log was like the previous one:
> >
> > [ 248.833978] ehci_hcd 0000:00:0b.1: alan start cur time 4294916032 last scan 4294885464
> > [ 248.833991] ehci_hcd 0000:00:0b.1: command 10035 cmd reg 10075 io watchdog 1 async count 10
> > [ 248.833998] ehci_hcd 0000:00:0b.1: async list:
> > [ 248.834006] ehci_hcd 0000:00:0b.1: qh ffff880149fcfe00 hw ffff8800af800000 dma af800000 next ffff880146d70380 hw_next af8009c2
> > [ 248.834013] ehci_hcd 0000:00:0b.1: qh ffff880146d70380 hw ffff8800af8009c0 dma af8009c0 next ffff880146c95b00 hw_next af800a82
> > [ 248.834020] ehci_hcd 0000:00:0b.1: qh ffff880146c95b00 hw ffff8800af800a80 dma af800a80 next ffff880149b51f00 hw_next af800cc2
> > [ 248.834027] ehci_hcd 0000:00:0b.1: qh ffff880149b51f00 hw ffff8800af800cc0 dma af800cc0 next ffff880145d17e80 hw_next af800f02
> > [ 248.834033] ehci_hcd 0000:00:0b.1: qh ffff880145d17e80 hw ffff8800af800f00 dma af800f00 next ffff88013d137180 hw_next af800c02
> > [ 248.834040] ehci_hcd 0000:00:0b.1: qh ffff88013d137180 hw ffff8800af800c00 dma af800c00 next ffff880148bc0000 hw_next af800d82
> > [ 248.834046] ehci_hcd 0000:00:0b.1: qh ffff880148bc0000 hw ffff8800af800d80 dma af800d80 next ffff8801410f9f00 hw_next af800b42
> > [ 248.834053] ehci_hcd 0000:00:0b.1: qh ffff8801410f9f00 hw ffff8800af800b40 dma af800b40 next ffff880147b8bc80 hw_next af8007e2
> > [ 248.834060] ehci_hcd 0000:00:0b.1: qh ffff880147b8bc80 hw ffff8800af8007e0 dma af8007e0 next ffff880140b49180 hw_next af800e42
> > [ 248.834066] ehci_hcd 0000:00:0b.1: qh ffff880140b49180 hw ffff8800af800e40 dma af800e40 next ffff880141f8ac00 hw_next af8008a2
> > [ 248.834073] ehci_hcd 0000:00:0b.1: qh ffff880141f8ac00 hw ffff8800af8008a0 dma af8008a0 next (null) hw_next af800002
> > [ 248.834080] ehci_hcd 0000:00:0b.1: This qh link time 4294885466 enqueue time 4294885466 td token 1f8c80 ov token 0
> > [ 248.834087] ehci_hcd 0000:00:0b.1: qh ffff880146d70380 naf800a82 info 42002210 40000000 qtd af81ccc0
> > [ 248.834095] ehci_hcd 0000:00:0b.1: overlay td ffff8800af8009d0 nae2531e0 00000001 t00000000 p0=af87fa9f
> > [ 248.834103] ehci_hcd 0000:00:0b.1: dma ae2531e0 td ffff8800ae2531e0 naf81ef60 00000001 t001f8c80 p0=af87fa80
> > [ 248.834111] ehci_hcd 0000:00:0b.1: dummy af81ef60 td ffff8800af81ef60 n00000001 00000001 t00000040 p0=00000000
> > [ 248.845154] ehci_hcd 0000:00:0b.1: giveback urb ffff88014980dcc0 actual 0
> > [ 248.845162] ehci_hcd 0000:00:0b.1: alan end
>
> This says that everything is correct, but the async schedule isn't
> running even though it is supposedly turned on. Goodness knows why
> not.
>
> > Note that there was not anymore the log line before "alan start".
> >
> > I suspect the previous error was something else, maybe something
> > it happens seldom, since sometimes I saw some timeout errors, but
> > they were almost always not a problem.
>
> Maybe. We need more debugging. Two changes:
>
> Firstly, in the code added by the earlier, larger patch, edit the
> alan_debug() function in ehci-hcd.c. Change the lines that say:
>
> ehci_dbg(ehci, "command %x cmd reg %x io watchdog %d async count %d\n",
> ehci->command, ehci_readl(ehci, &ehci->regs->command),
> ehci->need_io_watchdog, ehci->async_count);
>
> to this instead:
>
> ehci_dbg(ehci, "command %x cmd reg %x status reg %x\n",
> ehci->command, ehci_readl(ehci, &ehci->regs->command),
> ehci_readl(ehci, &ehci->regs->status));
>
> Secondly, apply the patch below on top of the last patch. It will
> tell us when the async schedule gets turned on and off.
>
> Alan Stern
>
>
>
> Index: usb-3.7/drivers/usb/host/ehci-timer.c
> ===================================================================
> --- usb-3.7.orig/drivers/usb/host/ehci-timer.c
> +++ usb-3.7/drivers/usb/host/ehci-timer.c
> @@ -126,9 +126,10 @@ static void ehci_poll_ASS(struct ehci_hc
>
> /* The status is up-to-date; restart or stop the schedule as needed */
> if (want == 0) { /* Stopped */
> - if (ehci->async_count > 0)
> + if (ehci->async_count > 0) {
> ehci_set_command_bit(ehci, CMD_ASE);
> -
> + ehci_dbg(ehci, "async on\n");
> + }
> } else { /* Running */
> if (ehci->async_count == 0) {
>
> @@ -143,6 +144,7 @@ static void ehci_poll_ASS(struct ehci_hc
> static void ehci_disable_ASE(struct ehci_hcd *ehci)
> {
> ehci_clear_command_bit(ehci, CMD_ASE);
> + ehci_dbg(ehci, "async off\n");
> }
>
>
--
piergiorgio
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