From patchwork Mon May 22 10:37:31 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lorenzo Pieralisi X-Patchwork-Id: 9739903 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 1B8AF6034C for ; Mon, 22 May 2017 10:36:56 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1342C286DE for ; Mon, 22 May 2017 10:36:56 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 078CA286EF; Mon, 22 May 2017 10:36:56 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 91732286DE for ; Mon, 22 May 2017 10:36:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=gRQ5AoKLDe3q7Xi8C+9TR0TkBNuQJoWh8J1vAyV1Ms0=; b=sBYDhrFPxqn/M/ wNkC5IKw6EvwXMnF7lZbaeU9i7koSnuedarkpUQXTzOs6qWsWiF2W4jwDQbzGuHNxI5YKN2W8QQic hnnn7mUfvQIL/3GM0YEOem/Jbp6abvS9MdDijyPUFs26d9J6oHU17UnKOXZ/ugUHol9pC49oL1FRH JxRvodPDoISlntM9RBv98TxbuZ8lPMs5AbiDKlhfYLcUcEHsMWtyPMGK3cPDZXUN4nZFbqr4iVwmc xnuaZtSyDfSbOkYmL2+X27Z6pVx7CDYpowV/7mSeMOURdnWO4OBl3vjiFDyDCHfzhlVKoySbLZoOM n5U5QaChH9cx4LNipPuA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1dCkho-0000SC-U7; Mon, 22 May 2017 10:36:52 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1dCkhl-0000Qv-L1 for linux-arm-kernel@lists.infradead.org; Mon, 22 May 2017 10:36:51 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 62DC51435; Mon, 22 May 2017 03:36:29 -0700 (PDT) Received: from red-moon (red-moon.cambridge.arm.com [10.1.206.55]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0A4BD3F23B; Mon, 22 May 2017 03:36:24 -0700 (PDT) Date: Mon, 22 May 2017 11:37:31 +0100 From: Lorenzo Pieralisi To: Sricharan R Subject: Re: [PATCH V4 3/4] ACPI/IORT: Ignore all errors except EPROBE_DEFER Message-ID: <20170522103730.GB7553@red-moon> References: <1495119257-26724-1-git-send-email-sricharan@codeaurora.org> <1495119257-26724-3-git-send-email-sricharan@codeaurora.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1495119257-26724-3-git-send-email-sricharan@codeaurora.org> User-Agent: Mutt/1.5.21 (2010-09-15) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20170522_033649_696884_0F73D33F X-CRM114-Status: GOOD ( 15.88 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: catalin.marinas@arm.com, will.deacon@arm.com, okaya@codeaurora.org, laurent.pinchart@ideasonboard.com, frowand.list@gmail.com, m.szyprowski@samsung.com, linux-arch@vger.kernel.org, tn@semihalf.com, joro@8bytes.org, magnus.damm@gmail.com, linux-acpi@vger.kernel.org, geert@linux-m68k.org, linux-pci@vger.kernel.org, lenb@kernel.org, devicetree@vger.kernel.org, arnd@arndb.de, linux-arm-msm@vger.kernel.org, j.neuschaefer@gmx.net, robh+dt@kernel.org, bhelgaas@google.com, linux-arm-kernel@lists.infradead.org, rjw@rjwysocki.net, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, hanjun.guo@linaro.org, sudeep.holla@arm.com, robin.murphy@arm.com Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Hi Sricharan, On Thu, May 18, 2017 at 08:24:16PM +0530, Sricharan R wrote: > While deferring the probe of IOMMU masters, xlate and > add_device callbacks called from iort_iommu_configure > can pass back error values like -ENODEV, which means > the IOMMU cannot be connected with that master for real > reasons. Before the IOMMU probe deferral, all such errors > were ignored. Now all those errors are propagated back, > killing the master's probe for such errors. Instead ignore > all the errors except EPROBE_DEFER, which is the only one > of concern and let the master work without IOMMU, thus > restoring the old behavior. > > Fixes: 5a1bb638d567 ("drivers: acpi: Handle IOMMU lookup failure with deferred probing or error") > Signed-off-by: Sricharan R > --- > [V4] Added this patch newly. > > drivers/acpi/arm64/iort.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c > index c5fecf9..16e101f 100644 > --- a/drivers/acpi/arm64/iort.c > +++ b/drivers/acpi/arm64/iort.c > @@ -782,6 +782,12 @@ const struct iommu_ops *iort_iommu_configure(struct device *dev) > if (err) > ops = ERR_PTR(err); > > + /* Ignore all other errors apart from EPROBE_DEFER */ > + if (IS_ERR(ops) && (PTR_ERR(ops) != -EPROBE_DEFER)) { > + dev_dbg(dev, "Adding to IOMMU failed: %ld\n", PTR_ERR(ops)); > + ops = NULL; > + } > + > return ops; > } > It is getting a bit convoluted. Is not it better to propagate the error back and let acpi_dma_configure() make a decision accordingly ? Something like: -- >8 -- diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index e39ec7b..3a10d757 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -1371,8 +1371,8 @@ int acpi_dma_configure(struct device *dev, enum dev_dma_attr attr) iort_set_dma_mask(dev); iommu = iort_iommu_configure(dev); - if (IS_ERR(iommu)) - return PTR_ERR(iommu); + if (IS_ERR(iommu) && PTR_ERR(iommu) == -EPROBE_DEFER) + return -EPROBE_DEFER; size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1); /*