Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934026AbaGQPcM (ORCPT ); Thu, 17 Jul 2014 11:32:12 -0400 Received: from mailout32.mail01.mtsvc.net ([216.70.64.70]:58277 "EHLO n23.mail01.mtsvc.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933006AbaGQPcJ (ORCPT ); Thu, 17 Jul 2014 11:32:09 -0400 Message-ID: <53C7EC6F.6060902@hurleysoftware.com> Date: Thu, 17 Jul 2014 11:31:59 -0400 From: Peter Hurley User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 MIME-Version: 1.0 To: balbi@ti.com, Sebastian Andrzej Siewior CC: linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Tony Lindgren , linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, Greg Kroah-Hartman , mika.westerberg@linux.intel.com Subject: Re: [PATCH 4/5] tty: serial: 8250 core: add runtime pm References: <1405521903-5877-1-git-send-email-bigeasy@linutronix.de> <1405521903-5877-5-git-send-email-bigeasy@linutronix.de> <20140716151604.GG1365@saruman.home> <53C6A050.2050409@linutronix.de> <20140716160614.GI1365@saruman.home> In-Reply-To: <20140716160614.GI1365@saruman.home> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Authenticated-User: 990527 peter@hurleysoftware.com X-MT-ID: 8FA290C2A27252AACF65DBC4A42F3CE3735FB2A4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/16/2014 12:06 PM, Felipe Balbi wrote: > On Wed, Jul 16, 2014 at 05:54:56PM +0200, Sebastian Andrzej Siewior wrote: >> On 07/16/2014 05:16 PM, Felipe Balbi wrote: >>> I wonder if you should get_sync() on start_tx() and only >>> put_autosuspend() at stop_tx(). I guess the outcome would be >>> largely the same, no ? >> >> I just opened minicom on ttyS0 and gave a try. start_tx() was invoked >> each time I pressed a key (sent a character). I haven't seen stop_tx() >> even after after I closed minicom. I guess stop_tx() is invoked if you >> switch half-duplex communication. > > that's bad, I expected stop to be called also after each character. The 8250 core auto-stops tx when the tx ring buffer is empty (except in the case of dma, where stopping tx isn't necessary). Regards, Peter Hurley -- 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/