On Mon, 13 Sep 2010, Jiri Slaby wrote: > Hi, > > by mistake when runtime PM is enabled by default for input devices, X > hangs on wacom open: > [<ffffffff814a00ea>] mutex_lock+0x1a/0x40 > [<ffffffffa02bc94b>] wacom_resume+0x3b/0x90 [wacom] > [<ffffffff81327a32>] usb_resume_interface+0xd2/0x190 > [<ffffffff81327b5d>] usb_resume_both+0x6d/0x110 > [<ffffffff81327c24>] usb_runtime_resume+0x24/0x40 > [<ffffffff8130a2cf>] __pm_runtime_resume+0x26f/0x450 > [<ffffffff8130a23a>] __pm_runtime_resume+0x1da/0x450 > [<ffffffff8130a53a>] pm_runtime_resume+0x2a/0x50 > [<ffffffff81328176>] usb_autopm_get_interface+0x26/0x60 > [<ffffffffa02bc626>] wacom_open+0x36/0x90 [wacom] > > wacom_open took wacom->lock and calls usb_autopm_get_interface which in > turn calls wacom_resume which tries to aquire the lock again. > > More details (dmesg including) at: > https://bugzilla.novell.com/show_bug.cgi?id=638506 > > Any ideas how to fix that properly? One possibility is for wacom_open simply not to acquire the lock until after the usb_autopm_get_interface call returns. And why does wacom_open have that assignment to wacom->irq->dev? The value was already set in wacom_probe. BTW, does anybody know why wacom_open calls usb_autopm_get_interface but wacom_close doesn't call usb_autopm_put_interface? Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
