From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752819AbaBZLGV (ORCPT ); Wed, 26 Feb 2014 06:06:21 -0500 Received: from moutng.kundenserver.de ([212.227.126.130]:52771 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751829AbaBZLCp (ORCPT ); Wed, 26 Feb 2014 06:02:45 -0500 From: Arnd Bergmann To: linux-kernel@vger.kernel.org Cc: Arnd Bergmann , Michael Schmitz , Geert Uytterhoeven , "James E.J. Bottomley" , linux-scsi@vger.kernel.org Subject: [PATCH 02/16] scsi: atari_scsi: fix sleep_on race Date: Wed, 26 Feb 2014 12:01:42 +0100 Message-Id: <1393412516-3762435-3-git-send-email-arnd@arndb.de> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1393412516-3762435-1-git-send-email-arnd@arndb.de> References: <1393412516-3762435-1-git-send-email-arnd@arndb.de> X-Provags-ID: V02:K0:TZXHjdMVycb9koJrEaNSPL3n3dk5mcodUcD3AsYWU99 bIUV1bDauKxZlwjareBgM3t4rIT9ZmMqNPyYNqZvRABvjyCt20 ytOsqHAaZIzauziTzMryu9GUL8MqbuYmILRMqYRWClU1rwRufP hwpFmbhsac6KALSDUUdVGCPw0Xzq0PtLFv5i0MAlcAKDQ5+zJ9 l6I4mzYVR0QIYXRrfdCfkk5foIfAnhZIfsZtS+WLWj5I2Bk+zm dB6S2kci/cQHi+zE5aY+J3rcoRdkjrDT6ksSZpVZrfzHGrpNxv lsQb7AWT9FynQyx644wPBm6y/GBIJS+OtotJMCPVEq71yfgX+z 3BXmePa1y1NhXk3NY9asGv+VopQwze0PpJ76y1zym Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org sleep_on is known broken and going away. The atari_scsi driver is one of two remaining users in the falcon_get_lock() function, which is a rather crazy piece of code. This does not attempt to fix the driver's locking scheme in general, but at least prevents falcon_get_lock from going to sleep when no other thread holds the same lock or tries to get it, and we no longer schedule with irqs disabled. Signed-off-by: Arnd Bergmann Cc: Michael Schmitz Cc: Geert Uytterhoeven Cc: James E.J. Bottomley Cc: linux-scsi@vger.kernel.org --- drivers/scsi/atari_scsi.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/drivers/scsi/atari_scsi.c b/drivers/scsi/atari_scsi.c index a3e6c8a..b33ce34 100644 --- a/drivers/scsi/atari_scsi.c +++ b/drivers/scsi/atari_scsi.c @@ -90,6 +90,7 @@ #include #include #include +#include #include #include @@ -549,8 +550,10 @@ static void falcon_get_lock(void) local_irq_save(flags); - while (!in_irq() && falcon_got_lock && stdma_others_waiting()) - sleep_on(&falcon_fairness_wait); + wait_event_cmd(falcon_fairness_wait, + !in_irq() && falcon_got_lock && stdma_others_waiting(), + local_irq_restore(flags), + local_irq_save(flags)); while (!falcon_got_lock) { if (in_irq()) @@ -562,7 +565,10 @@ static void falcon_get_lock(void) falcon_trying_lock = 0; wake_up(&falcon_try_wait); } else { - sleep_on(&falcon_try_wait); + wait_event_cmd(falcon_try_wait, + falcon_got_lock && !falcon_trying_lock, + local_irq_restore(flags), + local_irq_save(flags)); } } -- 1.8.3.2