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Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1i3KG1-000368-CY; Thu, 29 Aug 2019 13:14:33 +0000 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1i3KFy-00035n-VB for linux-arm-kernel@lists.infradead.org; Thu, 29 Aug 2019 13:14:32 +0000 Received: from lupine.hi.pengutronix.de ([2001:67c:670:100:3ad5:47ff:feaf:1a17] helo=lupine) by metis.ext.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1i3KFv-0003L0-Rd; Thu, 29 Aug 2019 15:14:27 +0200 Message-ID: <1567084467.5345.9.camel@pengutronix.de> Subject: Re: [PATCHv2 03/11] soc: ti: omap-prm: poll for reset complete during de-assert From: Philipp Zabel To: Tero Kristo , ssantosh@kernel.org, linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org, robh+dt@kernel.org Date: Thu, 29 Aug 2019 15:14:27 +0200 In-Reply-To: <20190828071941.32378-4-t-kristo@ti.com> References: <20190828071941.32378-1-t-kristo@ti.com> <20190828071941.32378-4-t-kristo@ti.com> X-Mailer: Evolution 3.22.6-1+deb9u2 Mime-Version: 1.0 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-arm-kernel@lists.infradead.org X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190829_061431_005619_B59B2252 X-CRM114-Status: GOOD ( 14.19 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: tony@atomide.com, devicetree@vger.kernel.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Tero, On Wed, 2019-08-28 at 10:19 +0300, Tero Kristo wrote: > Poll for reset completion status during de-assertion of reset, otherwise > the IP in question might be accessed before it has left reset properly. > > Signed-off-by: Tero Kristo > --- > drivers/soc/ti/omap_prm.c | 20 ++++++++++++++++++++ > 1 file changed, 20 insertions(+) > > diff --git a/drivers/soc/ti/omap_prm.c b/drivers/soc/ti/omap_prm.c > index fd5c431f8736..afeb70761b27 100644 > --- a/drivers/soc/ti/omap_prm.c > +++ b/drivers/soc/ti/omap_prm.c > @@ -127,6 +127,7 @@ static int omap_reset_deassert(struct reset_controller_dev *rcdev, > u32 v; > int st_bit; > bool has_rstst; > + int timeout = 0; > > if (!_is_valid_reset(reset, id)) > return -EINVAL; > @@ -153,6 +154,25 @@ static int omap_reset_deassert(struct reset_controller_dev *rcdev, > v &= ~(1 << id); > writel_relaxed(v, reset->prm->base + reset->prm->data->rstctrl); > > + if (!has_rstst) > + return 0; > + > + /* wait for the status to be set */ > + while (1) { > + v = readl_relaxed(reset->prm->base + reset->prm->data->rstst); > + v &= 1 << st_bit; > + if (v) > + break; > + timeout++; > + if (timeout > OMAP_RESET_MAX_WAIT) { > + pr_err("%s: timedout waiting for %s:%lu\n", __func__, > + dev_name(rcdev->dev), id); > + return -EBUSY; > + } > + > + udelay(1); > + } This looks like you could use readl_relaxed_poll_timeout(_atomic) regards Philipp _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel