From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Williamson Subject: Need to disable MSR interrupts in 8250 driver. Request for guidance... Date: Mon, 03 Jan 2011 09:15:10 -0500 Message-ID: <4D21D9EE.7070503@criticallink.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mail-vw0-f46.google.com ([209.85.212.46]:33755 "EHLO mail-vw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754745Ab1ACOPR (ORCPT ); Mon, 3 Jan 2011 09:15:17 -0500 Received: by vws16 with SMTP id 16so5747721vws.19 for ; Mon, 03 Jan 2011 06:15:16 -0800 (PST) Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: linux-serial@vger.kernel.org Cc: "davinci-linux-open-source@linux.davincidsp.com" Hello, I am working on platform from the davinci architecture that uses the 8520 UART driver. However, there are some configurations that do not have a valid CTS input pin (it is a multi-purpose pin on a SoC part, and it may be configured for other functions). These configurations can cause a pile of "false" MSR interrupts. If, in 8250.c, I set the UART_BUG_NOMSR flag as part of the up->bugs information, the problem clears up. The problem is that there is no way to pass bugs information via platform data. The link (below) contains a work-around patch that I had submitted to the davinci group. It was suggested that I get guidance from the folks on the davinci-serial list, and that I should consider figuring out a way to set the UART_BUG_NOMSR flag from the platform or initialization data. The patch submission also has a more detailed description of the problem for anyone interested. https://patchwork.kernel.org/patch/442671/ Should I create a new port type, add a new UPF_ flag in the flags field, figure out how to pass bugs information via platform data, or continue along the work-around path? Thanks for any insight. -Mike