From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Hurley Subject: Re: PROBLEM: BUG: scheduling while atomic in the 8250 serial driver Date: Sat, 01 Feb 2014 12:27:39 -0500 Message-ID: <52ED2E8B.2050908@hurleysoftware.com> References: <52ECED0D.4090202@ewanet.ch> <52ED07F1.60304@hurleysoftware.com> <20140201150436.GA8992@kroah.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mailout32.mail01.mtsvc.net ([216.70.64.70]:33236 "EHLO n23.mail01.mtsvc.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933102AbaBAR1r (ORCPT ); Sat, 1 Feb 2014 12:27:47 -0500 In-Reply-To: <20140201150436.GA8992@kroah.com> Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: Greg Kroah-Hartman Cc: Beat Bolli , linux-serial@vger.kernel.org On 02/01/2014 10:04 AM, Greg Kroah-Hartman wrote: > On Sat, Feb 01, 2014 at 09:42:57AM -0500, Peter Hurley wrote: >> You can't use low_latency; only devices that receive data in >> non-interrupt contexts (such as USB serial devices) can. > > USB serial devices get their data in interrupt context, until we fix USB > callbacks to be threaded, which might happen one day... Oh yeah, you're right. Weird. Back when I was writing the Firewire serial driver, I experimented with low_latency some but decided it wasn't worth the hassle. I could swear I was copying from some USB serial driver... Regards, Peter Hurley