From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 454D2C33CB3 for ; Tue, 28 Jan 2020 15:28:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 26063207FD for ; Tue, 28 Jan 2020 15:28:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726734AbgA1P2t (ORCPT ); Tue, 28 Jan 2020 10:28:49 -0500 Received: from foss.arm.com ([217.140.110.172]:59464 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726383AbgA1P2s (ORCPT ); Tue, 28 Jan 2020 10:28:48 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 286EB31B; Tue, 28 Jan 2020 07:28:48 -0800 (PST) Received: from [10.1.196.37] (e121345-lin.cambridge.arm.com [10.1.196.37]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DC3383F68E; Tue, 28 Jan 2020 07:28:46 -0800 (PST) Subject: Re: [PATCH 1/3] clk: rockchip: convert rk3399 pll type to use readl_poll_timeout To: Heiko Stuebner , linux-clk@vger.kernel.org Cc: sboyd@kernel.org, Heiko Stuebner , mturquette@baylibre.com, zhangqing@rock-chips.com, linux-kernel@vger.kernel.org, linux-rockchip@lists.infradead.org, linux-arm-kernel@lists.infradead.org, christoph.muellner@theobroma-systems.com References: <20200128100204.1318450-1-heiko@sntech.de> From: Robin Murphy Message-ID: Date: Tue, 28 Jan 2020 15:28:44 +0000 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20200128100204.1318450-1-heiko@sntech.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 28/01/2020 10:02 am, Heiko Stuebner wrote: > From: Heiko Stuebner > > Instead of open coding the polling of the lock status, use the > handy readl_poll_timeout for this. As the pll locking is normally > blazingly fast and we don't want to incur additional delays, we're > not doing any sleeps similar to for example the imx clk-pllv4 > and define a very safe but still short timeout of 1ms. > > Suggested-by: Stephen Boyd > Signed-off-by: Heiko Stuebner > --- > drivers/clk/rockchip/clk-pll.c | 21 ++++++++++----------- > 1 file changed, 10 insertions(+), 11 deletions(-) > > diff --git a/drivers/clk/rockchip/clk-pll.c b/drivers/clk/rockchip/clk-pll.c > index 198417d56300..43c9fd0086a2 100644 > --- a/drivers/clk/rockchip/clk-pll.c > +++ b/drivers/clk/rockchip/clk-pll.c > @@ -585,19 +585,18 @@ static const struct clk_ops rockchip_rk3066_pll_clk_ops = { > static int rockchip_rk3399_pll_wait_lock(struct rockchip_clk_pll *pll) > { > u32 pllcon; > - int delay = 24000000; > + int ret; > > - /* poll check the lock status in rk3399 xPLLCON2 */ > - while (delay > 0) { > - pllcon = readl_relaxed(pll->reg_base + RK3399_PLLCON(2)); > - if (pllcon & RK3399_PLLCON2_LOCK_STATUS) > - return 0; > + /* > + * Lock time typical 250, max 500 input clock cycles @24MHz > + * So define a very safe maximum of 1000us, meaning 24000 cycles. > + */ > + ret = readl_poll_timeout(pll->reg_base + RK3399_PLLCON(2), pllcon, > + pllcon & RK3399_PLLCON2_LOCK_STATUS, 0, 1000); Note that the existing I/O accessor was readl_relaxed(), but using plain readl_poll_timeout() switches it to regular readl(). It may well not matter, but since it's not noted as an intentional change it seemed worth pointing out. Robin. > + if (ret) > + pr_err("%s: timeout waiting for pll to lock\n", __func__); > > - delay--; > - } > - > - pr_err("%s: timeout waiting for pll to lock\n", __func__); > - return -ETIMEDOUT; > + return ret; > } > > static void rockchip_rk3399_pll_get_params(struct rockchip_clk_pll *pll, >