From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bruno =?UTF-8?B?UHLDqW1vbnQ=?= Subject: HID, driver interaction with device during probe defeated by 4ea5454203d991ec85264f64f89ca8855fce69b0 Date: Mon, 9 Apr 2012 00:03:06 +0200 Message-ID: <20120409000306.101c3427@neptune> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from smtprelay.restena.lu ([158.64.1.62]:42725 "EHLO smtprelay.restena.lu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755479Ab2DHWNJ (ORCPT ); Sun, 8 Apr 2012 18:13:09 -0400 Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: David Herrmann Cc: Jiri Kosina , linux-input@vger.kernel.org Hi, picolcd driver stopped working (probe fails) recently, probably in relation with commit 4ea5454203d991ec85264f64f89ca8855fce69b0 (HID: Fix race condition between driver core and ll-driver). The probe code does send a report to the HID device to query version information but times-out getting the response. What would be the proper approach to fix this chicken-egg problem? Semaphore introduced by above patch is only being released after driver probe function has returned but prevents and incoming reports from being delivered. Touching the semaphore inside driver looks like a bad idea to me... Thanks, Bruno