Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751650AbbESUqA (ORCPT ); Tue, 19 May 2015 16:46:00 -0400 Received: from shards.monkeyblade.net ([149.20.54.216]:48013 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751004AbbESUp5 (ORCPT ); Tue, 19 May 2015 16:45:57 -0400 Date: Tue, 19 May 2015 16:45:55 -0400 (EDT) Message-Id: <20150519.164555.1631069770118420652.davem@davemloft.net> To: joe@perches.com Cc: hofrat@osadl.org, samuel@sortiz.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] irda: irda-usb: use msecs_to_jiffies for conversions From: David Miller In-Reply-To: <1432045935.2870.152.camel@perches.com> References: <1432032711-7020-1-git-send-email-hofrat@osadl.org> <1432045935.2870.152.camel@perches.com> X-Mailer: Mew version 6.6 on Emacs 24.5 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Tue, 19 May 2015 13:45:57 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1346 Lines: 32 From: Joe Perches Date: Tue, 19 May 2015 07:32:15 -0700 > On Tue, 2015-05-19 at 12:51 +0200, Nicholas Mc Guire wrote: >> Converting milliseconds to jiffies by "val * HZ / 1000" is technically >> is not a clean solution as it does not handle all corner cases correctly. >> By changing the conversion to use msecs_to_jiffies(val) conversion is >> correct in all cases. >> >> in the current code: >> mod_timer(&self->rx_defer_timer, jiffies + (10 * HZ / 1000)); >> for HZ < 100 (e.g. CONFIG_HZ == 64|32 in alpha) this effectively results >> in no delay at all. > [] >> diff --git a/drivers/net/irda/irda-usb.c b/drivers/net/irda/irda-usb.c > [] >> @@ -848,7 +848,9 @@ static void irda_usb_receive(struct urb *urb) >> * Jean II */ >> self->rx_defer_timer.function = irda_usb_rx_defer_expired; >> self->rx_defer_timer.data = (unsigned long) urb; >> - mod_timer(&self->rx_defer_timer, jiffies + (10 * HZ / 1000)); >> + mod_timer(&self->rx_defer_timer, >> + jiffies + (msecs_to_jiffies(10))); > > The unnecessary () around msecs_to_jiffies could be removed. Agreed. -- 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/