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On Thu, 21 Apr 2016, Matthew Giassa wrote:
> Hi Alan,
>
> I've tested your latest patch, and here is a subset of the output in
> `dmesg':
...
> [ 44.975704] enable LPM
> [ 44.975707] CPU: 4 PID: 2491 Comm: FlyCap2 Tainted: G E
> 4.5.0-astern-logging+ #11
> [ 44.975708] Hardware name: ASUS All Series/Z97-PRO(Wi-Fi ac), BIOS
> 2012 09/30/2014
> [ 44.975708] 0000000000000000 ffff880217c9bd50 ffffffff813c2ccc
> ffff8802362c5000
> [ 44.975710] ffff88023308a000 ffff880217c9bd78 ffffffff815ceadf
> ffff88023308a000
> [ 44.975711] ffff8802362c5000 ffffffff81ce5860 ffff880217c9bd98
> ffffffff815ceb1c
> [ 44.975713] Call Trace:
> [ 44.975715] [<ffffffff813c2ccc>] dump_stack+0x63/0x87
> [ 44.975717] [<ffffffff815ceadf>] usb_enable_lpm+0x10f/0x120
> [ 44.975718] [<ffffffff815ceb1c>] usb_unlocked_enable_lpm+0x2c/0x40
> [ 44.975719] [<ffffffff815dd10e>]
> usb_driver_claim_interface+0xbe/0x110
> [ 44.975720] [<ffffffff815e386b>] claimintf+0x5b/0x80
> [ 44.975721] [<ffffffff815e6960>] usbdev_do_ioctl+0xd10/0x1180
> [ 44.975723] [<ffffffff815e6dfe>] usbdev_ioctl+0xe/0x20
> [ 44.975724] [<ffffffff812174a6>] do_vfs_ioctl+0x96/0x590
> [ 44.975725] [<ffffffff810fb491>] ? SyS_futex+0x71/0x150
> [ 44.975727] [<ffffffff81217a19>] SyS_ioctl+0x79/0x90
> [ 44.975729] [<ffffffff817e2036>] entry_SYSCALL_64_fastpath+0x16/0x75
...
Now I see the problem. The patch changed usb_probe_interface, but I
forgot to change usb_driver_claim_interface also. Try this version of
the patch instead. It also has the extra debugging output, but now it
shouldn't ever get triggered.
Alan Stern
Index: usb-4.x/include/linux/usb.h
===================================================================
--- usb-4.x.orig/include/linux/usb.h
+++ usb-4.x/include/linux/usb.h
@@ -1069,7 +1069,7 @@ struct usbdrv_wrap {
* for interfaces bound to this driver.
* @soft_unbind: if set to 1, the USB core will not kill URBs and disable
* endpoints before calling the driver's disconnect method.
- * @disable_hub_initiated_lpm: if set to 0, the USB core will not allow hubs
+ * @disable_hub_initiated_lpm: if set to 1, the USB core will not allow hubs
* to initiate lower power link state transitions when an idle timeout
* occurs. Device-initiated USB 3.0 link PM will still be allowed.
*
Index: usb-4.x/drivers/usb/core/driver.c
===================================================================
--- usb-4.x.orig/drivers/usb/core/driver.c
+++ usb-4.x/drivers/usb/core/driver.c
@@ -284,7 +284,7 @@ static int usb_probe_interface(struct de
struct usb_device *udev = interface_to_usbdev(intf);
const struct usb_device_id *id;
int error = -ENODEV;
- int lpm_disable_error;
+ int lpm_disable_error = -ENODEV;
dev_dbg(dev, "%s\n", __func__);
@@ -336,12 +336,14 @@ static int usb_probe_interface(struct de
* setting during probe, that should also be fine. usb_set_interface()
* will attempt to disable LPM, and fail if it can't disable it.
*/
- lpm_disable_error = usb_unlocked_disable_lpm(udev);
- if (lpm_disable_error && driver->disable_hub_initiated_lpm) {
- dev_err(&intf->dev, "%s Failed to disable LPM for driver %s\n.",
- __func__, driver->name);
- error = lpm_disable_error;
- goto err;
+ if (driver->disable_hub_initiated_lpm) {
+ lpm_disable_error = usb_unlocked_disable_lpm(udev);
+ if (lpm_disable_error) {
+ dev_err(&intf->dev, "%s Failed to disable LPM for
driver %s\n.",
+ __func__, driver->name);
+ error = lpm_disable_error;
+ goto err;
+ }
}
/* Carry out a deferred switch to altsetting 0 */
@@ -391,7 +393,8 @@ static int usb_unbind_interface(struct d
struct usb_interface *intf = to_usb_interface(dev);
struct usb_host_endpoint *ep, **eps = NULL;
struct usb_device *udev;
- int i, j, error, r, lpm_disable_error;
+ int i, j, error, r;
+ int lpm_disable_error = -ENODEV;
intf->condition = USB_INTERFACE_UNBINDING;
@@ -399,12 +402,13 @@ static int usb_unbind_interface(struct d
udev = interface_to_usbdev(intf);
error = usb_autoresume_device(udev);
- /* Hub-initiated LPM policy may change, so attempt to disable LPM until
+ /* If hub-initiated LPM policy may change, attempt to disable LPM until
* the driver is unbound. If LPM isn't disabled, that's fine because it
* wouldn't be enabled unless all the bound interfaces supported
* hub-initiated LPM.
*/
- lpm_disable_error = usb_unlocked_disable_lpm(udev);
+ if (driver->disable_hub_initiated_lpm)
+ lpm_disable_error = usb_unlocked_disable_lpm(udev);
/*
* Terminate all URBs for this interface unless the driver
@@ -505,7 +509,7 @@ int usb_driver_claim_interface(struct us
struct device *dev;
struct usb_device *udev;
int retval = 0;
- int lpm_disable_error;
+ int lpm_disable_error = -ENODEV;
if (!iface)
return -ENODEV;
@@ -526,12 +530,14 @@ int usb_driver_claim_interface(struct us
iface->condition = USB_INTERFACE_BOUND;
- /* Disable LPM until this driver is bound. */
- lpm_disable_error = usb_unlocked_disable_lpm(udev);
- if (lpm_disable_error && driver->disable_hub_initiated_lpm) {
- dev_err(&iface->dev, "%s Failed to disable LPM for driver
%s\n.",
- __func__, driver->name);
- return -ENOMEM;
+ /* See the comment about disabling LPM in usb_probe_interface(). */
+ if (driver->disable_hub_initiated_lpm) {
+ lpm_disable_error = usb_unlocked_disable_lpm(udev);
+ if (lpm_disable_error) {
+ dev_err(&iface->dev, "%s Failed to disable LPM for
driver %s\n.",
+ __func__, driver->name);
+ return -ENOMEM;
+ }
}
/* Claimed interfaces are initially inactive (suspended) and
Index: usb-4.x/drivers/usb/core/devio.c
===================================================================
--- usb-4.x.orig/drivers/usb/core/devio.c
+++ usb-4.x/drivers/usb/core/devio.c
@@ -738,6 +738,8 @@ struct usb_driver usbfs_driver = {
.resume = driver_resume,
};
+int alantest;
+
static int claimintf(struct usb_dev_state *ps, unsigned int ifnum)
{
struct usb_device *dev = ps->dev;
@@ -757,8 +759,11 @@ static int claimintf(struct usb_dev_stat
intf = usb_ifnum_to_if(dev, ifnum);
if (!intf)
err = -ENOENT;
- else
+ else {
+ alantest = 1;
err = usb_driver_claim_interface(&usbfs_driver, intf, ps);
+ alantest = 0;
+ }
if (err == 0)
set_bit(ifnum, &ps->ifclaimed);
return err;
@@ -778,7 +783,9 @@ static int releaseintf(struct usb_dev_st
if (!intf)
err = -ENOENT;
else if (test_and_clear_bit(ifnum, &ps->ifclaimed)) {
+ alantest = 1;
usb_driver_release_interface(&usbfs_driver, intf);
+ alantest = 0;
err = 0;
}
return err;
Index: usb-4.x/drivers/usb/core/hub.c
===================================================================
--- usb-4.x.orig/drivers/usb/core/hub.c
+++ usb-4.x/drivers/usb/core/hub.c
@@ -33,6 +33,8 @@
#include "hub.h"
#include "otg_whitelist.h"
+extern int alantest;
+
#define USB_VENDOR_GENESYS_LOGIC 0x05e3
#define HUB_QUIRK_CHECK_PORT_AUTOSUSPEND 0x01
@@ -4054,6 +4056,11 @@ int usb_disable_lpm(struct usb_device *u
if ((udev->u1_params.timeout == 0 && udev->u2_params.timeout == 0))
return 0;
+ if (alantest) {
+ pr_info("disable LPM\n");
+ dump_stack();
+ }
+
/* If LPM is enabled, attempt to disable it. */
if (usb_disable_link_state(hcd, udev, USB3_LPM_U1))
goto enable_lpm;
@@ -4121,6 +4128,11 @@ void usb_enable_lpm(struct usb_device *u
if (!hub)
return;
+ if (alantest) {
+ pr_info("enable LPM\n");
+ dump_stack();
+ }
+
port_dev = hub->ports[udev->portnum - 1];
if (port_dev->usb3_lpm_u1_permit)
--
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