From mboxrd@z Thu Jan 1 00:00:00 1970 From: Grant Edwards Subject: Re: What to set uart_port->irq to for polled driver? Date: Thu, 28 Feb 2013 18:43:28 +0000 (UTC) Message-ID: References: <1362076338.3337.3.camel@thor.lan> Return-path: Received: from plane.gmane.org ([80.91.229.3]:51138 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756486Ab3B1Snn (ORCPT ); Thu, 28 Feb 2013 13:43:43 -0500 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1UB8SX-0006OI-92 for linux-serial@vger.kernel.org; Thu, 28 Feb 2013 19:44:01 +0100 Received: from dsl.comtrol.com ([64.122.56.22]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 28 Feb 2013 19:44:01 +0100 Received: from grant.b.edwards by dsl.comtrol.com with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 28 Feb 2013 19:44:01 +0100 Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: linux-serial@vger.kernel.org On 2013-02-28, Peter Hurley wrote: > On Wed, 2013-02-13 at 15:24 +0000, Grant Edwards wrote: >> For a polled serial driver that doesn't use interrupts, to what should >> the "irq" field in the uart_port structure be set? Should it be 0? >> Should it be the unused IRQ associated with the PCI card slot in which >> the board is found? > > Doesn't look supported, but adding the support doesn't look difficult. > At the very least, a patch is required so that on port shutdown, the > core doesn't synchronize_irq(). Does the call ty synchronize_irq() do any harm? AFAICT, it will just cause a short delay if handling of that IRQ is in-progress. I currently set the "irq" field to the IRQ number that would be used by the board if I did choose to enable interrupts. That seems to work fine (with rather limited testing). -- Grant Edwards grant.b.edwards Yow! We just joined the at civil hair patrol! gmail.com