Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932583AbWCWTJ7 (ORCPT ); Thu, 23 Mar 2006 14:09:59 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932588AbWCWTJ7 (ORCPT ); Thu, 23 Mar 2006 14:09:59 -0500 Received: from smtp-104-thursday.nerim.net ([62.4.16.104]:37135 "EHLO kraid.nerim.net") by vger.kernel.org with ESMTP id S932583AbWCWTJ6 (ORCPT ); Thu, 23 Mar 2006 14:09:58 -0500 Date: Thu, 23 Mar 2006 20:10:30 +0100 From: Jean Delvare To: LKML Cc: Arjan van de Ven , Ingo Molnar , "Mark A.Greer" , Randy Vinson Subject: [PATCH, RFC] Stop using tasklet in ds1374 RTC driver Message-Id: <20060323201030.ccded642.khali@linux-fr.org> X-Mailer: Sylpheed version 2.2.3 (GTK+ 2.6.10; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2702 Lines: 100 Hi all, I have the following patch, which addresses a might-sleep-in-tasklet issue in the ds1374 driver. I'm not too sure if the new code is right or not, as I have never been using workqueues before, and I also don't have a DS1374 chip to test my changes on. Can anyone comment on the patch and tell me if anything is wrong? Can anyone with a DS1374 chip please test it? I want this to be fixed now, because in -mm the ds1374 driver also uses the new mutex implementation, which is not allowed in tasklets, but is OK in workqueues. Thanks. * * * * * A tasklet is not suitable for what the ds1374 driver does: neither sleeping nor mutex operations are allowed in tasklets, and ds1374_set_tlet may do both. We can use a workqueue instead, where both sleeping and mutex operations are allowed. Signed-off-by: Jean Delvare --- drivers/i2c/chips/ds1374.c | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-) --- linux-2.6.16-git.orig/drivers/i2c/chips/ds1374.c 2006-03-23 10:21:48.000000000 +0100 +++ linux-2.6.16-git/drivers/i2c/chips/ds1374.c 2006-03-23 19:37:25.000000000 +0100 @@ -27,6 +27,7 @@ #include #include #include +#include #define DS1374_REG_TOD0 0x00 #define DS1374_REG_TOD1 0x01 @@ -139,7 +140,7 @@ return t1; } -static void ds1374_set_tlet(ulong arg) +static void ds1374_set_work(void *arg) { ulong t1, t2; int limit = 10; /* arbitrary retry limit */ @@ -168,19 +169,15 @@ static ulong new_time; -static DECLARE_TASKLET_DISABLED(ds1374_tasklet, ds1374_set_tlet, - (ulong) & new_time); +static struct workqueue_struct *ds1374_workqueue; + +static DECLARE_WORK(ds1374_work, ds1374_set_work, &new_time); int ds1374_set_rtc_time(ulong nowtime) { new_time = nowtime; - if (in_interrupt()) - tasklet_schedule(&ds1374_tasklet); - else - ds1374_set_tlet((ulong) & new_time); - - return 0; + return queue_work(ds1374_workqueue, &ds1374_work); } /* @@ -204,6 +201,8 @@ client->adapter = adap; client->driver = &ds1374_driver; + ds1374_workqueue = create_singlethread_workqueue("ds1374"); + if ((rc = i2c_attach_client(client)) != 0) { kfree(client); return rc; @@ -227,7 +226,7 @@ if ((rc = i2c_detach_client(client)) == 0) { kfree(i2c_get_clientdata(client)); - tasklet_kill(&ds1374_tasklet); + destroy_workqueue(ds1374_workqueue); } return rc; } -- Jean Delvare - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/