From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 597B83033D8 for ; Thu, 17 Sep 2026 06:59:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789628371; cv=none; b=PJAWLQSHrIO1uBsEG/y++Q1Q6sycGNLyllSyT4VRdk/OxAR9MurQIeBOSOjc6zQtzHjfC9zDoO3BelBHAzoUFIx2/Jyw7VVjoUW4MAqik6pzuRtChuKqPakoZR+AUw68cBtqewV5xvvsvCMOSyG7/fEcbjO7tpse086DYQyVRx0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789628371; c=relaxed/simple; bh=hJ5GJ4vLuXnoyUYhLQDMtKomFHUpowUPUgS4aTwNKpY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Se1Cq7cMmayxMi8Fg9adhv9FNeXRkgQlgBhdER3WiECSq+KTTb5T/WLU6OQKxIEHHH7NtSIiQPpH8TS0mhjmYemN1QnPfAVxsefnuCGq1efbkm5Jj7fyMg/6KDoO672w6/uGigI8IA90rZOSYIEea1Wi9mk34inuWT4SMjISGZc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=PMUDvTfj; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="PMUDvTfj" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1789628369; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=uTBRx/POh6sMNSgm0GJh52YtrZBru3mV1Q9aul2DNLU=; b=PMUDvTfjMH0ZTXt6A6sh0wLgUHB3Bz0FqHUhQgU7QrExDKmi1IS8HYAZzoSoUBvC7CyDMF 7c97AORxUk5FuChU8m8xBZMmyyfZpkUjK+s/ojlgZXQ+tKpWJbwURA07R1hjjE3zGkPVB+ w/SYi4JQAUvxlKUSCAjjcKLBVXaNtCg= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-311-B3nzCZyuN6qmTGsSQWl-GQ-1; Thu, 17 Sep 2026 02:59:26 -0400 X-MC-Unique: B3nzCZyuN6qmTGsSQWl-GQ-1 X-Mimecast-MFC-AGG-ID: B3nzCZyuN6qmTGsSQWl-GQ_1789628364 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 1CBC21954B13; Thu, 17 Sep 2026 06:59:24 +0000 (UTC) Received: from fedora.redhat.corp (headnet05.pony-001.prod.iad2.dc.redhat.com [10.2.32.117]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 9524230001BE; Thu, 17 Sep 2026 06:59:19 +0000 (UTC) From: Jose Ignacio Tornos Martinez To: helgaas@kernel.org Cc: alex@shazbot.org, ath11k@lists.infradead.org, ath12k@lists.infradead.org, bhelgaas@google.com, jjohnson@kernel.org, jtornosm@redhat.com, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-wireless@vger.kernel.org, mani@kernel.org, mhi@lists.linux.dev Subject: Re: [PATCH v13] PCI: Add device-specific reset for Qualcomm devices Date: Thu, 17 Sep 2026 08:59:18 +0200 Message-ID: <20260917065918.13357-1-jtornosm@redhat.com> In-Reply-To: <20260915223634.GA878346@bhelgaas> References: <20260915223634.GA878346@bhelgaas> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Hi Bjorn, Thanks for the review. > I guess you are saying that some kind of reset *does* work > fine in normal, clean VM termination? If reset works fine > for normal VM termination but not for VM crash, do we have > any idea why they are different? It depends on the device: - For the modems (SDX62/SDX65), without a proper reset capability, these devices never successfully initialize even on first VM assignment. - For the WLAN devices (WCN6855/WCN7850), the reset fails in both cases, but on clean VM shutdown the guest driver's .shutdown/.remove callbacks properly deinitialize the device (stop DMA, disable interrupts, etc.), so it ends up in a known-good state even without a successful reset. On unclean termination (crash, force-off), the guest driver callbacks never run, the device stays in an undefined state, and without a working reset it cannot be reused. I will try to clarify this better in the commit messages for v14. > Since these basically copy code from other drivers, is there > an opportunity to remove it from those drivers and use this > instead? Yes, that could be a follow-up after this lands. > This looks like two patches squashed together. If there's > any other reason to touch this patch, I would split them > apart. Ok, I will split the WLAN and modem resets into separate patches for v14. Thanks Best regards Jose Ignacio