From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bruno =?UTF-8?B?UHLDqW1vbnQ=?= Date: Sat, 18 Aug 2012 13:48:28 +0000 Subject: Re: [PATCH 0/7] HID: picoLCD updates Message-Id: <20120818154828.0e992bfe@neptune.home> List-Id: References: <20120818144039.0356cc7c@neptune.home> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit To: Alan Stern Cc: Jiri Kosina , linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fbdev@vger.kernel.org On Sat, 18 August 2012 Alan Stern wrote: > On Sat, 18 Aug 2012, Bruno Prémont wrote: > > On Thu, 16 August 2012 Jiri Kosina wrote: > > > On Thu, 16 Aug 2012, Bruno Prémont wrote: > > > > > > > > I don't really understand this explanation. Once usb_kill_urb() returns, > > > > > the URB should be available for future use (and therefore all queues > > > > > completely drained). > > > > > > > > I won't have time today to check, though my guess is that on each > > > > echo $usb-id > bind; echo $usb-id > unbind > > > > under /sys/bus/hid/drivers/hid-picolcd/ the USB urb queue fills a bit does > > > > not get cleared. > > > > > > > > Is usb_kill_urb() called when unbinding just the specific hid driver? > > > > > > Yup, through hid_hw_stop() -> usbhid_stop(). > > > > > > > If so my short timing between bind/unbind must be triggering something > > > > else... > > > > > > > > Otherwise I'm missing something as at first time I got no "output queue full" > > > > messages, but as I repeated the bind/unbind sequences the prints per bind/unbind > > > > iteration increased in number. > > > > > > > > Anyhow, on Friday evening/week-end I will continue digging and report back with my > > > > findings. > > > > Huh, after changing some of the hid-picolcd data in order to have less racy > > coupling between hid and framebuffer I'm now dying way too often in _mmx_memcpy > > and most of the time I don't get a (complete) trace... > > There was a similar problem reported recently. It turned out to be > caused by a __devinitconst annotation attached to a usb_device_id > table. > > If there are any __devinit* annotations in the hid-picolcd driver, you > should see if removing them helps. There is no such annotation around in hid-picolcd. One thing I just though about, how does usbhid handle the calls to usbhid_submit_report() when hid_hw_stop()/hid_hw_close() have already been called? I will attempt to see if it makes a difference to shortcut my usbhid_submit_report() calls from the point on I have called hid_hw_close()... Bruno