From: Alan Stern <stern@rowland.harvard.edu>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Jonathan Corbet <corbet@lwn.net>,
<Ingo@sc8-sf-spam2-b.sourceforge.net>,
<linux-usb-devel@lists.sourceforge.net>,
Roman Zippel <zippel@linux-m68k.org>,
<linux-kernel@vger.kernel.org>,
Thomas Gleixner <tglx@linutronix.de>, Molnar <mingo@elte.hu>
Subject: Re: [linux-usb-devel] [PATCH] msleep() with hrtimers
Date: Thu, 9 Aug 2007 11:08:03 -0400 (EDT) [thread overview]
Message-ID: <Pine.LNX.4.44L0.0708091105150.3559-100000@iolanthe.rowland.org> (raw)
In-Reply-To: <20070809001640.ec2f3bfb.akpm@linux-foundation.org>
On Thu, 9 Aug 2007, Andrew Morton wrote:
> This failed the Vaio test. I guess it triggered a USB bug.
>
> With this patch applied, when I hotplug my wireless mouse, the little LED
> on the mouse comes on for a second or so then goes out and no pointy clicky
> for me.
>
> It says:
>
> [ 152.481522] usb 1-1: new low speed USB device using uhci_hcd and address 2
>
>
> Without this patch applied, I get
>
> [ 195.935445] usb 2-1: new low speed USB device using uhci_hcd and address 2
> [ 196.116183] usb 2-1: configuration #1 chosen from 1 choice
> [ 196.198362] input: Microsoft Microsoft Wireless Optical Mouse 1.00 as /class/input/input7
> [ 196.223724] input: USB HID v1.11 Mouse [Microsoft Microsoft Wireless Optical Mouse 1.00] on usb-0000:00:1d.1-1
> [ 196.224570] usb 2-1: new device found, idVendor=045e, idProduct=00e1
> [ 196.224579] usb 2-1: new device strings: Mfr=1, Product=2, SerialNumber=0
> [ 196.224585] usb 2-1: Product: Microsoft Wireless Optical Mouse 1.00
> [ 196.224590] usb 2-1: Manufacturer: Microsoft
>
> and lots of pointy clickiness.
>
> I would assume that there is some msleep() in USB which is too short, and
> the present wild rounding-up which msleep() does covered up the
> incorrectly-chosen sleep duration.
>
> I'm using HZ=250 (http://userweb.kernel.org/~akpm/config-sony.txt) and it
> could well be that the mouse would fail just by going to HZ=1000, but I
> didn't bother testing that.
>
> Could one of the USB developers please suggest which msleep()(s) I should
> start looking at?
It could be one of the calls in drivers/usb/core/hub.c, however almost
all of them are at least 10 ms already. There's a 0-ms msleep near the
start of hub_port_wait_reset() which might cause problems.
It will be easier to pin down the culprit if you turn on
CONFIG_USB_DEBUG.
Alan Stern
next prev parent reply other threads:[~2007-08-09 15:08 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-08-03 18:37 [PATCH] msleep() with hrtimers Jonathan Corbet
2007-08-03 18:54 ` Ingo Molnar
2007-08-03 19:19 ` Roman Zippel
2007-08-03 19:46 ` Arjan van de Ven
2007-08-03 19:58 ` Roman Zippel
2007-08-03 23:53 ` Arjan van de Ven
2007-08-04 3:00 ` Roman Zippel
2007-08-04 19:19 ` Arjan van de Ven
2007-08-06 0:09 ` Roman Zippel
2007-08-06 0:43 ` Arjan van de Ven
2007-08-06 1:03 ` Roman Zippel
2007-08-06 5:39 ` Arjan van de Ven
2007-08-06 10:03 ` Roman Zippel
2007-08-06 10:20 ` Manu Abraham
2007-08-06 15:53 ` Arjan van de Ven
2007-08-07 10:40 ` Manu Abraham
2007-08-07 12:45 ` Roman Zippel
2007-08-08 4:15 ` Arjan van de Ven
2007-08-09 19:31 ` Denis Vlasenko
2007-08-09 20:01 ` Denis Vlasenko
2007-08-07 19:40 ` Andrew Morton
2007-08-07 23:16 ` Roman Zippel
2007-08-07 23:29 ` Andrew Morton
2007-08-08 3:47 ` Roman Zippel
2007-08-08 4:14 ` Andrew Morton
2007-08-09 22:31 ` Roman Zippel
2007-08-08 11:55 ` Andi Kleen
2007-08-08 11:09 ` Manu Abraham
2007-08-08 11:52 ` Andi Kleen
2007-08-08 11:59 ` Manu Abraham
2007-08-09 7:16 ` Andrew Morton
2007-08-09 15:08 ` Alan Stern [this message]
2007-11-28 10:29 ` Andrew Morton
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