Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752417AbbEGXe4 (ORCPT ); Thu, 7 May 2015 19:34:56 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:53701 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752310AbbEGXet (ORCPT ); Thu, 7 May 2015 19:34:49 -0400 Message-ID: <554BF697.7010208@codeaurora.org> Date: Thu, 07 May 2015 16:34:47 -0700 From: Stephen Boyd User-Agent: Mozilla/5.0 (X11; Linux i686 on x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 To: Pramod Gurav CC: linux-arm-msm@vger.kernel.org, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org, bryanh@codeaurora.org, jslaby@suse.cz Subject: Re: [PATCH v3 2/3] tty: serial: msm: Remove duplicate operations on clocks in startup/shutdown References: <1428668396-6955-1-git-send-email-gpramod@codeaurora.org> <1428668396-6955-2-git-send-email-gpramod@codeaurora.org> <55281068.3000309@codeaurora.org> In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1874 Lines: 45 On 04/29/15 08:45, Pramod Gurav wrote: > Thanks Stephen for review. > > On Fri, April 10, 2015 11:33 pm, Stephen Boyd wrote: >> On 04/10/15 05:19, Pramod Gurav wrote: >>> @@ -683,8 +679,7 @@ static void msm_power(struct uart_port *port, >>> unsigned int state, >>> >>> switch (state) { >>> case 0: >>> - clk_prepare_enable(msm_port->clk); >>> - clk_prepare_enable(msm_port->pclk); >>> + msm_init_clock(port); >> Hm... now we would call msm_serial_set_mnd_regs() whenever we power on >> the port? Presumably we only need to do that once when we probe (or when >> we resume from a sleep state that resets the registers, i.e. >> hibernation) but I guess we're getting saved by the fact that the >> if/else if pair in msm_serial_set_mnd_regs_from_uartclk would never be >> true after the first time we call it? > I tried replacing msm_init_clock() call with msm_serial_set_mnd_regs() in > msm_startup() as msm_startup gets called just after msm_power() so that > clk_prepare_enable() is followed by mnd settings. But it does not get the > kernel booted for some reason. That's concerning. Did you also drop the call to msm_init_clock() from msm_power() as is done in this patch? If that's done then it seems that nothing would be different besides the removal of clk_prepare_enable() in msm_startup(). > > So, can I get a acked-by for this patch or you still think it can be done > in a better way? Using msm_init_clock() in the msm_power() doesn't look symmetrical so if we can avoid it I would prefer that. -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project -- 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/