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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 95026C433EF for ; Mon, 24 Jan 2022 04:27:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241390AbiAXE1o (ORCPT ); Sun, 23 Jan 2022 23:27:44 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40528 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229508AbiAXE1n (ORCPT ); Sun, 23 Jan 2022 23:27:43 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7D8A1C06173B; Sun, 23 Jan 2022 20:27:43 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id D3B0560C5B; Mon, 24 Jan 2022 04:27:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 77B0AC340E1; Mon, 24 Jan 2022 04:27:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1642998462; bh=bu82sJ+NjeI3uuIOGsgPoe/ycAxxYC9Q8Zij5mql5gA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=PVPWgMTA02LQv8gB3uq7owgnzrPNGUiCM4YT3xgA77kT6KA3hA+SQD6QN0msD/Hhh bnxZRUK+WooyMo9annjlUjtKlHUuMVzljUt9X02FV+yeuGeHfADMz0bMXp/tJ3dTaN UEkj7/W6wPcOIhyawaXAdMj67OENQNURc59pzr3gBez7deoSmd7ZxCo5Ok5JDFxJ0m U6ys6+KAfHCd2gqMENcXlc9LumQlcsyNP4OfXmPdY1N6IQEvHZxvTb8p2SCyNhMNWQ MpwxXqdzMwf//SxFa3MvBz98MdB29y4NdAh5HNeTeXTGcPYrd8IYgUJH5ZExpI0nnN mSzKOSaLraSGg== Date: Mon, 24 Jan 2022 09:57:38 +0530 From: Vinod Koul To: Ansuel Smith Cc: Andy Gross , Bjorn Andersson , Kishon Vijay Abraham I , linux-arm-msm@vger.kernel.org, linux-phy@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] drivers: phy: qcom: ipq806x-usb: conver latch function to pool macro Message-ID: References: <20220117002641.26773-1-ansuelsmth@gmail.com> <20220117002641.26773-2-ansuelsmth@gmail.com> <61ed6a44.1c69fb81.35728.5e8b@mx.google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <61ed6a44.1c69fb81.35728.5e8b@mx.google.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 23-01-22, 15:46, Ansuel Smith wrote: > On Sun, Jan 23, 2022 at 05:22:18PM +0530, Vinod Koul wrote: > > On 17-01-22, 01:26, Ansuel Smith wrote: > > > Convert latch function to readl pool macro to tidy things up. > > > > > > Signed-off-by: Ansuel Smith > > > --- > > > drivers/phy/qualcomm/phy-qcom-ipq806x-usb.c | 17 +++++------------ > > > 1 file changed, 5 insertions(+), 12 deletions(-) > > > > > > diff --git a/drivers/phy/qualcomm/phy-qcom-ipq806x-usb.c b/drivers/phy/qualcomm/phy-qcom-ipq806x-usb.c > > > index 6788e0e8272a..ab2d1431546d 100644 > > > --- a/drivers/phy/qualcomm/phy-qcom-ipq806x-usb.c > > > +++ b/drivers/phy/qualcomm/phy-qcom-ipq806x-usb.c > > > @@ -112,6 +112,9 @@ > > > #define SS_CR_READ_REG BIT(0) > > > #define SS_CR_WRITE_REG BIT(0) > > > > > > +#define LATCH_SLEEP 40 > > > +#define LATCH_TIMEOUT 100 > > > + > > > struct usb_phy { > > > void __iomem *base; > > > struct device *dev; > > > @@ -156,19 +159,9 @@ static inline void usb_phy_write_readback(struct usb_phy *phy_dwc3, > > > > > > static int wait_for_latch(void __iomem *addr) > > > { > > > - u32 retry = 10; > > > - > > > - while (true) { > > > - if (!readl(addr)) > > > - break; > > > > we break if read returns non zero value... > > > > Do you know what is the value expected? > > > > If I understand the logic here, we write a value and we wait for it to > get applied. To confirm that we execute a writel and then we readl the > same address until it does return a value. That is the way used to > understand that the write process has finished and that the value has > been applied/we can write again. > > > > - > > > - if (--retry == 0) > > > - return -ETIMEDOUT; > > > - > > > - usleep_range(10, 20); > > > - } > > > + u32 val; > > > > Okay this contains garbage.. > > I think I didn't understand, val value will get replaced by readl in > the pool_timeout function. > > > > > > > - return 0; > > > + return readl_poll_timeout(addr, val, !val, LATCH_SLEEP, LATCH_TIMEOUT); > > > > and we are waiting for it read a garbage value! > > > > Again could be very confused and wrong but the pool_timeout macro does > the exact same thing of the wait_for_latch function with th only > difference of handling the sleep differently. We put in val the return > of readl and the break condition as !val. Or I didn't understand the > concern about garbage value. Sorry I read the readl_poll_timeout wrongly, this seems correct, I will pick these now. -- ~Vinod