On Sun, 17 Feb 2013, Ronald wrote: > Current head gives this when I plug a 'Mass Storage Device' into a 2.0 hub: > > [ 842.760400] hub 1-0:1.0: unable to enumerate USB device on port 3 > [ 843.080058] usb 1-3: new high-speed USB device number 48 using ehci-pci > [ 858.230072] usb 1-3: device descriptor read/64, error -110 > [ 873.490070] usb 1-3: device descriptor read/64, error -110 > > Reverting the following commit makes it work again: > > commit 55bcdce8a8228223ec4d17d8ded8134ed265d2c5 > Author: Alan Stern <[email protected]> > Date: Fri Jan 25 16:52:45 2013 -0500 > > USB: EHCI: remove ASS/PSS polling timeout > > This patch (as1647) attempts to work around a problem that seems to > affect some nVidia EHCI controllers. They sometimes take a very long > time to turn off their async or periodic schedules. I don't know if > this is a result of other problems, but in any case it seems wise not > to depend on schedule enables or disables taking effect in any > specific length of time. > > The patch removes the existing 20-ms timeout for enabling and > disabling the schedules. The driver will now continue to poll the > schedule state at 1-ms intervals until the controller finally decides > to obey the most recent command issued by the driver. Just in case > this hides a problem, a debugging message will be logged if the > controller takes longer than 20 polls. > > I don't know if this will actually fix anything, but it can't hurt.
On Thu, 14 Feb 2013, Paul Hartman wrote: > I ran git bisect on kernel and found this commit. "but it can't hurt" > famous last words :) > > 269ef9f3805a5ec17ddf3dd5f13d5e09598c155b is the first bad commit > commit 269ef9f3805a5ec17ddf3dd5f13d5e09598c155b > Author: Alan Stern <[email protected]> > Date: Fri Jan 25 16:52:45 2013 -0500 > > USB: EHCI: remove ASS/PSS polling timeout Okay. I have no idea what could be going wrong, but obviously we need to find out. The patch below will add a bunch of debugging info related to this commit. For it to work, you will need to enable CONFIG_USB_DEBUG when you build your kernels. Please post the output from "dmesg", showing what happens starting from boot-up until a device fails. Alan Stern Index: usb-3.8/drivers/usb/host/ehci-hcd.c =================================================================== --- usb-3.8.orig/drivers/usb/host/ehci-hcd.c +++ usb-3.8/drivers/usb/host/ehci-hcd.c @@ -287,6 +287,9 @@ static void ehci_quiesce (struct ehci_hc /* wait for any schedule enables/disables to take effect */ temp = (ehci->command << 10) & (STS_ASS | STS_PSS); handshake(ehci, &ehci->regs->status, STS_ASS | STS_PSS, temp, 16 * 125); + ehci_dbg(ehci, "quiesce: temp %x status %x\n", temp, + ehci_readl(ehci, &ehci->regs->status) & + (STS_ASS | STS_PSS)); /* then disable anything that's still active */ spin_lock_irq(&ehci->lock); @@ -296,6 +299,9 @@ static void ehci_quiesce (struct ehci_hc /* hardware can take 16 microframes to turn off ... */ handshake(ehci, &ehci->regs->status, STS_ASS | STS_PSS, 0, 16 * 125); + ehci_dbg(ehci, "quiesce2: status %x\n", + ehci_readl(ehci, &ehci->regs->status) & + (STS_ASS | STS_PSS)); } /*-------------------------------------------------------------------------*/ Index: usb-3.8/drivers/usb/host/ehci-timer.c =================================================================== --- usb-3.8.orig/drivers/usb/host/ehci-timer.c +++ usb-3.8/drivers/usb/host/ehci-timer.c @@ -110,6 +110,8 @@ static void ehci_poll_ASS(struct ehci_hc want = (ehci->command & CMD_ASE) ? STS_ASS : 0; actual = ehci_readl(ehci, &ehci->regs->status) & STS_ASS; + ehci_dbg(ehci, "ASS want %x actual %x count %d\n", + want, actual, ehci->ASS_poll_count); if (want != actual) { @@ -126,8 +128,10 @@ 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_dbg(ehci, "Set ASE\n"); ehci_set_command_bit(ehci, CMD_ASE); + } } else { /* Running */ if (ehci->async_count == 0) { @@ -142,6 +146,7 @@ static void ehci_poll_ASS(struct ehci_hc /* Turn off the async schedule after a brief delay */ static void ehci_disable_ASE(struct ehci_hcd *ehci) { + ehci_dbg(ehci, "Clear ASE"); ehci_clear_command_bit(ehci, CMD_ASE); } @@ -157,6 +162,8 @@ static void ehci_poll_PSS(struct ehci_hc want = (ehci->command & CMD_PSE) ? STS_PSS : 0; actual = ehci_readl(ehci, &ehci->regs->status) & STS_PSS; + ehci_dbg(ehci, "PSS want %x actual %x count %d\n", + want, actual, ehci->PSS_poll_count); if (want != actual) { @@ -172,8 +179,10 @@ static void ehci_poll_PSS(struct ehci_hc /* The status is up-to-date; restart or stop the schedule as needed */ if (want == 0) { /* Stopped */ - if (ehci->periodic_count > 0) + if (ehci->periodic_count > 0) { + ehci_dbg(ehci, "Set PSE\n"); ehci_set_command_bit(ehci, CMD_PSE); + } } else { /* Running */ if (ehci->periodic_count == 0) { @@ -188,6 +197,7 @@ static void ehci_poll_PSS(struct ehci_hc /* Turn off the periodic schedule after a brief delay */ static void ehci_disable_PSE(struct ehci_hcd *ehci) { + ehci_dbg(ehci, "Clear PSE"); ehci_clear_command_bit(ehci, CMD_PSE); } -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
