From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qv1-f47.google.com (mail-qv1-f47.google.com [209.85.219.47]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DAEA41A5B86 for ; Tue, 22 Apr 2025 19:00:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.47 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745348440; cv=none; b=XRpWiqIXpUDMUkVBc5IyrpXZia09cKapeNBOY/KuuPf3Ass+297NoZSrNQ5CEsIrEZSKF61rJ8f89dbevYekBrqSo98IQg+TmZmBwtvuXJuNC04wy2NJB2biZwexEE0q08MOQ0IN/slCEhQ0a1mYGr5o3Nc8dnVpTzqPyVfSZE4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745348440; c=relaxed/simple; bh=4QLSLmrkPbs1yBBussuVmcH9d86k1ZJ8t0dZp5NXcyc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=oorc+cMnhwa3luzoU3l6YdXK0JvUDJ+eFMJmp7lnL436oW/c4sD9sx3cC9aU/IW2OJnpixK8dgXpIAP8SeiZawjGnZre8OEdIFe7uZ29KjHV2UZY/zNxjNIX4Y1x/lq3fpHQP3Q7gVtPOqezBHbIqWBwPwaTo5YLcMVG1pj89/I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ziepe.ca; spf=pass smtp.mailfrom=ziepe.ca; dkim=pass (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca header.b=JY8owS40; arc=none smtp.client-ip=209.85.219.47 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ziepe.ca Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ziepe.ca Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca header.b="JY8owS40" Received: by mail-qv1-f47.google.com with SMTP id 6a1803df08f44-6e8fce04655so51895486d6.3 for ; Tue, 22 Apr 2025 12:00:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ziepe.ca; s=google; t=1745348437; x=1745953237; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=TMh0izLSzqmAU5ORZxGehcX6J35ZOvbIe3zUy9tlNbQ=; b=JY8owS40K0jtYFjGrIcxtLhyDsimWfnz3h5yTgIVzRuElVJmlJtejUKPgbU/d59FzH MSC5YMdutpF5U5TrzKTZ4tEEAnoX31AJvZJi9BcoxUsjNBlsZwT/XLGs3PQdnqSRtbSf Tz9+BEKtRg033DJQzjJWU6M0t+3S6Csle0omxMsJXQxtBB9Nl+cJ0kA9OPbLljaBYiO6 1BEiewxh8X5Cad7DJj/PMq7mXBGxiWqpmD+Yktr5aKLE94WyqP9nRUuvDv7TL8h5L8Bg b68MuACOKY5ZBE28Tnzo6CdslZSUTJKarqMcGjp55aEhLW6I6THokC/tX36ovO0y4Wif 8w5A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1745348437; x=1745953237; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=TMh0izLSzqmAU5ORZxGehcX6J35ZOvbIe3zUy9tlNbQ=; b=iWYIlWyi7HDre0QdvikPPkTfGkcviV7yGNnU+1p5AZcjTNCdqLRP2pz7hJcTihxLbm 29DbNtjQXJx34X4AGxyGRAq7AvtXvE+iDbYY6riQ7DFoLrKqIeQ3N09jKkI4s+57koWi NuD3zKPCMOW5zTazBv7oit7t+MIgKsKP7cI7Ypa4jmPIAaH+mAdztDcg9wQd+W20Gair iXrwQnDDSUgQNearecEqwjUdmUXvQEi+lwPE9SvboYWyykZW3O+A7HdorE3T+F33hHlL ibsvBh3rcrKAjLWKqc8i8vjfYMpkZOGuupMxt/Vl4LgNDKx0frihOGSzAva1PHwAWbtx 5VJA== X-Forwarded-Encrypted: i=1; AJvYcCWon6k/q038goCqeA2aqWzxXHHM+ji3nXZmNXDDwpt5f/kEdjYmCTDWMEZM5RjimfrWYq/phnp9JzAbfhs=@vger.kernel.org X-Gm-Message-State: AOJu0YwTpPGLPPPqhY7EJpBG9HMrnucgKo+HF1PlMe4mbrPAUHjH1PFG ztnVTbUOOrmc50AXFDs/f+eQxy3bcJX4bGTrWX4KLP0joUKqT6YwV9YJtEO5dXA= X-Gm-Gg: ASbGncsAebmhiT30f5L+5ISiRTl6hx35FxpYC2aKslK4KPGWekEz/hrSGKS4ufg31o6 ZkoCLjbVeQLqyAjZuLX0A1aPjVzB4j74LAhJdJJCV/nvGCcfT4badLi2kJi3JE5NBW6HcNTYij5 rT6DmrPkInRpzFVgtgj38Zq7ZXSDFqItRiev+MPCm2Q2RWfUAE99xrIXhW/OcoAv8XGHfIjUMIL h5uby2U4F9O8cAsQ5eK1fx1JX/L6HrSqvidUitJ10AxMroV2aWU1HESanbyka7Mf3n3XZXsyRFV hhC6kZkCKbp1kEfhMss5zapMTf8sO5s1WI7t63BZ6MWlqdjeGFnBEBPRj3mYlvPiapz6qNyApZ8 AOyEzefP7SsqpHq5KSA8= X-Google-Smtp-Source: AGHT+IHbq+pHzTQuxxdUufVp0+5UWeEWnmEdvfzQVGDaZiAVyxBLUWwXVLbiir8zvtHTZQ/owxmlMQ== X-Received: by 2002:a05:6214:3008:b0:6ea:d361:a4ca with SMTP id 6a1803df08f44-6f2c46557e7mr318335806d6.32.1745348437625; Tue, 22 Apr 2025 12:00:37 -0700 (PDT) Received: from ziepe.ca (hlfxns017vw-142-167-219-86.dhcp-dynamic.fibreop.ns.bellaliant.net. [142.167.219.86]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-6f2c2c21da6sm60863536d6.98.2025.04.22.12.00.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 22 Apr 2025 12:00:36 -0700 (PDT) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1u7IrE-00000006vVF-1Cvg; Tue, 22 Apr 2025 16:00:36 -0300 Date: Tue, 22 Apr 2025 16:00:36 -0300 From: Jason Gunthorpe To: William McVicker Cc: Robin Murphy , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , "Rafael J. Wysocki" , Len Brown , Russell King , Greg Kroah-Hartman , Danilo Krummrich , Stuart Yoder , Laurentiu Tudor , Nipun Gupta , Nikhil Agarwal , Joerg Roedel , Will Deacon , Rob Herring , Saravana Kannan , Bjorn Helgaas , linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, iommu@lists.linux.dev, devicetree@vger.kernel.org, linux-pci@vger.kernel.org, Charan Teja Kalla Subject: Re: [PATCH v2 4/4] iommu: Get DT/ACPI parsing into the proper probe path Message-ID: <20250422190036.GA1213339@ziepe.ca> References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Mon, Apr 21, 2025 at 02:19:35PM -0700, William McVicker wrote: > diff --git a/drivers/base/platform.c b/drivers/base/platform.c > index 1813cfd0c4bd..6d124447545c 100644 > --- a/drivers/base/platform.c > +++ b/drivers/base/platform.c > @@ -1440,8 +1440,8 @@ static void platform_shutdown(struct device *_dev) > > static int platform_dma_configure(struct device *dev) > { > - struct platform_driver *drv = to_platform_driver(dev->driver); > struct fwnode_handle *fwnode = dev_fwnode(dev); > + struct platform_driver *drv; > enum dev_dma_attr attr; > int ret = 0; > > @@ -1451,8 +1451,12 @@ static int platform_dma_configure(struct device *dev) > attr = acpi_get_dma_attr(to_acpi_device_node(fwnode)); > ret = acpi_dma_configure(dev, attr); > } > - /* @drv may not be valid when we're called from the IOMMU layer */ > - if (ret || !dev->driver || drv->driver_managed_dma) > + /* @dev->driver may not be valid when we're called from the IOMMU layer */ > + if (ret || !dev->driver) > + return ret; > + > + drv = to_platform_driver(dev->driver); > + if (drv->driver_managed_dma) > return ret; > > ret = iommu_device_use_default_domain(dev); The diagnosis looks right to me, but pedantically I think it should have a READ_ONCE(): struct driver *drv = READ_ONCE(dev->driver); And then never touch dev->driver again in the function. Send a proper patch? Jason