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 DE0503D45E4 for ; Tue, 12 May 2026 17:17:20 +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=1778606242; cv=none; b=TfsOIVqr9xFZCcf+C8haLhFp/q38eDD+TMHPO0H+dxbwer8fo+X66V8GfQb4tB8emL0lOF91hUBncZ4BHkJZa8kMcGufBJSZByFQPZqBu63/yXqnQOMejG3O347AtTDZEUR2Z2lLMm/BKn7qcllPjgVviVFahwME3kjco8YgSmo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778606242; c=relaxed/simple; bh=Oe/GIsy89lagNeD0WEvmK0wnd8GTxbtSRowCVJCo/cU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=a61Xac6ZeTPHRlrAyWgs7DhjASSp1wTUhKlmNx/YG/2jRGcMvVvHqf3eBQh4gvE42YAfiFht3EddSz0p7AB/bGnY2PuYiqYAILD//ZB4z/4fjjXiqhS8q9fh3mEEPsWkigqnw67TWBr9n1GwxTcz9D+CaJp0HzrhETuzswu9Fqg= 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=dU9PXVvd; 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="dU9PXVvd" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1778606240; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Oe/GIsy89lagNeD0WEvmK0wnd8GTxbtSRowCVJCo/cU=; b=dU9PXVvdN8q7hA+xFPFP/6E23uMZANb9QKt7BMJ6ti8AbMedZQI1ehvzt3ZGVlABAdepTo ykyQWp7fke91yOM4jd7u4iBdbOwGvPYFnXmEmbxvpW1FZgtUuBwzxz5vCvmwQwOS4L4JBP MGN2NuZlbgoyexmW+EV1AxCM6QNmY/4= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-561-OgCnxmSiMES3zTvADWRj8g-1; Tue, 12 May 2026 13:17:16 -0400 X-MC-Unique: OgCnxmSiMES3zTvADWRj8g-1 X-Mimecast-MFC-AGG-ID: OgCnxmSiMES3zTvADWRj8g_1778606235 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (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-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 86FE71800283; Tue, 12 May 2026 17:17:15 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.44.48.159]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id ABD9A19560A2; Tue, 12 May 2026 17:17:13 +0000 (UTC) From: Jose Ignacio Tornos Martinez To: alex@shazbot.org Cc: bhelgaas@google.com, jtornosm@redhat.com, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org Subject: Re: [PATCH v2] PCI: Force PM reset for Qualcomm devices with NoSoftRst+ Date: Tue, 12 May 2026 19:17:11 +0200 Message-ID: <20260512171712.910994-1-jtornosm@redhat.com> In-Reply-To: <20260511133643.73a16e69@shazbot.org> References: <20260511133643.73a16e69@shazbot.org> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Hello Alex, Thank you again for your detailed feedback and help >>> What does reset_methods sysfs attribute report for these devices on an >>> unpatched kernel? Sorry for my earlier confusion about CONFIG_PCI_RESET_SYSFS - I now understand the reset_method sysfs file has been available for a long time without any config option. Testing confirms only "bus" reset is available on default kernel for these Qualcomm devices. PM reset returns -ENOTTY (blocked by NoSoftRst+ flag), and FLR is not advertised. This confirms the default kernel has no working reset method for these devices. > Then why aren't we setting quirks to use quirk_no_bus_reset() for these > devices? You're right. I am going to try quirk_no_bus_reset() to disable the broken SBR method. > PS - D3cold might be an interesting reset method that could be implemented > for single function endpoints in slots that support it. I like the suggestion, I am going to implement a generic d3cold as a general PCI core reset method for single-function devices (not only for Qualcomm). I have seen that using pci_set_power_state(dev, PCI_D3cold), if no _PR3 support by the platform, it will use D3hot fallback. The combination of quirk_no_bus_reset() + general d3cold reset method can provide a much better solution for these devices and the new reset method allows the configuration if necessary. I'll send a next version with this. Thanks Best regards José Ignacio