From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 9FCDD3803EE for ; Thu, 22 Jan 2026 19:38:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769110683; cv=none; b=M2p++gJD4bmIBitzSaHHxvfaq6ZW+XxVDR/ISmIv/ZTBeBKsGZOBXa/VEF2I7RWjx291/aTsQTAvlAnz+RkkYB5RfuhY3KlivXFPjJNHjh/oYoM6PMx31FxGGmi0CI0k4Gwn0IACVuLaOJ++qDtg/m6S/ELjym7g1gDo23XgkBw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769110683; c=relaxed/simple; bh=YOz2HhCbiWKOnnroW1rgmPl9l0qvLq8bzycAVgB3rNc=; h=From:To:Subject:Date:Message-ID:In-Reply-To:References: Content-Type:MIME-Version; b=Kv3f22hUvN24XznPXBK42Q6FPbZtCIe0O2CBIQi3Ust7qEeZSGVP4kN2Rl0j7SXwnXVHw+PUQsO0YfZweR0tLn8pKzYtkxbkZJjS1/KlPakLbEThmiXUr61hVAmFAiEmlTJRZKxGekBynDpFhFETBkGZF47SIq0SM8rnLnEgG+E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=uVmyuUaX; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="uVmyuUaX" Received: by smtp.kernel.org (Postfix) with ESMTPS id 44126C2BC86 for ; Thu, 22 Jan 2026 19:38:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1769110682; bh=YOz2HhCbiWKOnnroW1rgmPl9l0qvLq8bzycAVgB3rNc=; h=From:To:Subject:Date:In-Reply-To:References:From; b=uVmyuUaXVWxc5oh56kqj65S8wCbYBgWZOjTRMVgQUj2P4K9xL//VWY5XiRLlUGyZu 8KWUaPzbMd+GkjSRqZAplXra0whW+b9MnD7QA9t2Q35vob1eH1dwTOQX5ZvmeVcjZ1 +1oybU2PVy5uDNJEfrumUl/aUhbnHOyymRk09sQ6bztfgHIKlLo+3kLTYDTXQdtNMz Mu2KP/z98paE9stNLWa11CBKJj1hplwoWoF+EKaksDcdCtBil4cE2uYO6vpgHnTAea l2o1j3SjFz4Wf18h9n0/TmzSnnUvaFAoZFum+TEavtyX/2IKiiw8tjdNV7r0tig88d S5hs6Bh0M9COg== Received: by aws-us-west-2-korg-bugzilla-1.web.codeaurora.org (Postfix, from userid 48) id 3A329C41616; Thu, 22 Jan 2026 19:38:02 +0000 (UTC) From: bugzilla-daemon@kernel.org To: linux-usb@vger.kernel.org Subject: [Bug 215740] kernel warning: DMA-API: xhci_hcd: cacheline tracking EEXIST, overlapping mappings aren't supported Date: Thu, 22 Jan 2026 19:38:01 +0000 X-Bugzilla-Reason: None X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: AssignedTo drivers_usb@kernel-bugs.kernel.org X-Bugzilla-Product: Drivers X-Bugzilla-Component: USB X-Bugzilla-Version: 2.5 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: linux@roeck-us.net X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P1 X-Bugzilla-Assigned-To: drivers_usb@kernel-bugs.kernel.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugzilla.kernel.org/ Auto-Submitted: auto-generated Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 https://bugzilla.kernel.org/show_bug.cgi?id=3D215740 --- Comment #47 from Guenter Roeck (linux@roeck-us.net) --- I (and Google, for that matter) long since went beyond that after the above feedback ("Equally important, however, is the question of why the people experiencing this problem turned on CONFIG_DMA_API_DEBUG in the first place. That setting is meant only for kernel testing and it drastically reduces performance."). For context, we don't enable CONFIG_DMA_API_DEBUG in production images. We enable it in test images to catch problems which are only caught in debug images. Getting false positives in such images doesn't help and hides real problems. So we gave up trying to fix the problem in the upstream kernel and implemen= ted a (downstream) workaround which excludes the "hub" and "xhcd_hcd" drivers f= rom DMA cacheline tracking. That may not be perfect, but it does the trick for = us. --=20 You may reply to this email to add a comment. You are receiving this mail because: You are watching the assignee of the bug.=