From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.wantstofly.org (hmm.wantstofly.org [213.239.204.108]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7E2B51B4257 for ; Sat, 5 Sep 2026 14:21:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.239.204.108 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788618070; cv=none; b=Tf1ioTkmIJss5qXz9Y/dPVEFYRliFHTkvdk/v67xnKTJ7OMpPOio3wBM+l6L6kKxfzSxaR5e2L3GPh5INQuKNxCUM5pbCdb208H8fNNvC2tUXc3x2gjt1uohIFvNpmXiPRxCa0CLdTekLVMEsp85bSF6uOCG3BE6upCyvpj9tmc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788618070; c=relaxed/simple; bh=zOfTrSfVO0NmACetR6+0WVaG3jH3tC/bZJbeYdSi28s=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=vBaPuACuKPZNvQkTW4Vn02QIldLGOU424Swh90kurq2WQlv/BAKahJFguuwRmCEVfrSLIpBFT0mrttwx88Lb352GrPE47iFOM562ZmTqGIQNNWMSKJxJpM2fY3up+ZckY9KXwc/nWHYso7xaoRerpusyAgEAET6h8uC/WqQR0Z4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=wantstofly.org; spf=pass smtp.mailfrom=wantstofly.org; arc=none smtp.client-ip=213.239.204.108 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=wantstofly.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=wantstofly.org Received: by mail.wantstofly.org (Postfix, from userid 1000) id 2AAE57F1F4; Sat, 05 Sep 2026 17:13:05 +0300 (EEST) Date: Sat, 5 Sep 2026 17:13:05 +0300 From: Lennert Buytenhek To: Mikael Etienne Cc: cassel@kernel.org, mario.limonciello@amd.com, roland.waltersson@netinsight.net, artmoty@gmail.com, linux-ide@vger.kernel.org, david.laight.linux@gmail.com, alvinwylim@gmail.com Subject: Re: [PATCH] ahci: force 32-bit DMA for JMicron JMB582/JMB585 Message-ID: References: <78dae3f6-3b3d-43c8-b2a2-595fd6e6a00b@amd.com> <07efa8b1-c5ef-4a61-8b0c-45f68d02d9f5@amd.com> <178854093896.541085.18395405788748617410@gmail.com> Precedence: bulk X-Mailing-List: linux-ide@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: <178854093896.541085.18395405788748617410@gmail.com> On Fri, Sep 04, 2026 at 11:55:38PM +0700, Mikael Etienne wrote: > The EFR field is probably the most direct discriminant. If Arthur, > Alvin and Lennert posted the same line, the "different IOMMU versions" > hypothesis could be tested immediately, with no extra hardware: [...] To echo what Niklas said, the DMA problem I was seeing a while ago with the ASM106x was purely an issue with the ARM106x itself, that is, a device-internal IOVA address width restriction, and had nothing to do with the IOMMU in my system. I was seeing AMD IOMMU I/O page faults in my particular case, but only because the system I originally encountered the issue in was an AMD-based system where the ASM106x happened to be behind an (AMD) IOMMU which was by default enabled in an isolating fashion, and the device was indeed causing I/O page faults, due to an IOVA address with restriction in the device itself, and the AMD IOMMU correctly signaled those I/O page faults, and the AMD IOMMU was not at fault for the device causing those I/O page faults, and I did subsequently reproduce the issue on an Intel-based system, where the ASM106x was causing the exact same I/O page faults -- that is, after the Intel IOMMU was manually enabled, which it wasn't (and maybe still isn't?) by default. In other words, I think that the issue I was seeing with the ASM106x should probably be left out of consideration in the context of the current discussion, where it appears from a distance that the (AMD) IOMMU in the reporter's system is somehow implicated in the corruption and misbehavior they are seeing.