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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 5A7D7C43381 for ; Tue, 19 Mar 2019 16:45:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3401E206B7 for ; Tue, 19 Mar 2019 16:45:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727859AbfCSQpP (ORCPT ); Tue, 19 Mar 2019 12:45:15 -0400 Received: from metis.ext.pengutronix.de ([85.220.165.71]:42299 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726857AbfCSQpO (ORCPT ); Tue, 19 Mar 2019 12:45:14 -0400 Received: from lupine.hi.pengutronix.de ([2001:67c:670:100:3ad5:47ff:feaf:1a17] helo=lupine) by metis.ext.pengutronix.de with esmtp (Exim 4.89) (envelope-from ) id 1h6HrS-0006lW-Rb; Tue, 19 Mar 2019 17:45:10 +0100 Message-ID: <1553013910.6482.11.camel@pengutronix.de> Subject: Re: [PATCH 5/5] drm/tegra: sor: Implement acquire/release for reset From: Philipp Zabel To: Thierry Reding Cc: Jonathan Hunter , linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org Date: Tue, 19 Mar 2019 17:45:10 +0100 In-Reply-To: <20190221152557.8534-5-thierry.reding@gmail.com> References: <20190221152557.8534-1-thierry.reding@gmail.com> <20190221152557.8534-5-thierry.reding@gmail.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.22.6-1+deb9u1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 2001:67c:670:100:3ad5:47ff:feaf:1a17 X-SA-Exim-Mail-From: p.zabel@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2019-02-21 at 16:25 +0100, Thierry Reding wrote: > From: Thierry Reding > > By implementing the acquire/release protocol, the SOR reset can be > shared with other drivers that also adhere to this protocol, such as the > PMC driver that uses the same reset as part of the powergate and -ungate > implementation using generic power domains. > > Runtime PM makes sure that the operations are executed in the right > order, and the reset core has error handling and WARNs in place to make > sure the acquire/release protocol is followed. > > Signed-off-by: Thierry Reding > --- > drivers/gpu/drm/tegra/sor.c | 21 ++++++++++++++++++++- > 1 file changed, 20 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/tegra/sor.c b/drivers/gpu/drm/tegra/sor.c > index 40057106f5f3..5be5a0817dfe 100644 > --- a/drivers/gpu/drm/tegra/sor.c > +++ b/drivers/gpu/drm/tegra/sor.c > @@ -2871,6 +2871,13 @@ static int tegra_sor_init(struct host1x_client *client) > * kernel is possible. > */ > if (sor->rst) { > + err = reset_control_acquire(sor->rst); > + if (err < 0) { > + dev_err(sor->dev, "failed to acquire SOR reset: %d\n", > + err); > + return err; > + } > + > err = reset_control_assert(sor->rst); > if (err < 0) { > dev_err(sor->dev, "failed to assert SOR reset: %d\n", > @@ -2894,6 +2901,8 @@ static int tegra_sor_init(struct host1x_client *client) > err); > return err; > } > + > + reset_control_release(sor->rst); > } > > err = clk_prepare_enable(sor->clk_safe); > @@ -3331,7 +3340,7 @@ static int tegra_sor_probe(struct platform_device *pdev) > goto remove; > } > > - sor->rst = devm_reset_control_get(&pdev->dev, "sor"); > + sor->rst = devm_reset_control_get_exclusive_released(&pdev->dev, "sor"); > if (IS_ERR(sor->rst)) { > err = PTR_ERR(sor->rst); > > @@ -3519,6 +3528,8 @@ static int tegra_sor_suspend(struct device *dev) > dev_err(dev, "failed to assert reset: %d\n", err); > return err; > } > + > + reset_control_release(sor->rst); > } > > usleep_range(1000, 2000); > @@ -3542,9 +3553,17 @@ static int tegra_sor_resume(struct device *dev) > usleep_range(1000, 2000); > > if (sor->rst) { > + err = reset_control_acquire(sor->rst); > + if (err < 0) { > + dev_err(dev, "failed to acquire reset: %d\n", err); > + clk_disable_unprepare(sor->clk); > + return err; > + } > + > err = reset_control_deassert(sor->rst); > if (err < 0) { > dev_err(dev, "failed to deassert reset: %d\n", err); > + reset_control_release(sor->rst); > clk_disable_unprepare(sor->clk); > return err; > } Reviewed-by: Philipp Zabel regards Philipp