From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bmailout1.hostsharing.net (bmailout1.hostsharing.net [83.223.95.100]) (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 52DDD16D9AF; Fri, 31 Jan 2025 12:09:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=83.223.95.100 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738325404; cv=none; b=KEY1GqzvYm392Qj9qH7GjU3+O+aeYBv0+4qV63MTMOXH9e3UFFe5qj3VKRG9Zh18vhGSqdwN5j6ZoOsp0C3kNLSt1cCdnN4jmTfzFzawagpwaGCQgD/dcK+mapUofhCESFRhjdohTeEug9iaFqqbyAeQ/lSnnztpiIquPCBozPY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738325404; c=relaxed/simple; bh=jZGcq+yg1AZLUIKLtsjmrWCl4GzT6CMuM7zP/fm4DVs=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=h6DWJZFCPR6Yr/SFnSlEXll14qCvEspW5F3pN6LTWCJvVsdCNpFNI659H5afzMKVjLM6GgLy9t7fyFP9ETEil/Byga2ZowuS1ThgqjgpdhVhtHUbpKmQIZrgv8mkuBS7JK2qSIx+szLjHSBkg2I6gX1fn4REzSOVkG+DwRV1eUI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=wunner.de; spf=none smtp.mailfrom=h08.hostsharing.net; arc=none smtp.client-ip=83.223.95.100 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=wunner.de Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=h08.hostsharing.net Received: from h08.hostsharing.net (h08.hostsharing.net [83.223.95.28]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "*.hostsharing.net", Issuer "RapidSSL TLS RSA CA G1" (verified OK)) by bmailout1.hostsharing.net (Postfix) with ESMTPS id C388B3000C9A0; Fri, 31 Jan 2025 13:09:51 +0100 (CET) Received: by h08.hostsharing.net (Postfix, from userid 100393) id BD70AAAAB43; Fri, 31 Jan 2025 13:09:51 +0100 (CET) Date: Fri, 31 Jan 2025 13:09:51 +0100 From: Lukas Wunner To: Naveen Kumar P Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Bjorn Helgaas Subject: Re: Assistance Needed: PCIe Device BAR Reset Issue Message-ID: References: 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=us-ascii Content-Disposition: inline In-Reply-To: On Fri, Jan 31, 2025 at 03:37:26PM +0530, Naveen Kumar P wrote: > PCIe Device: PLDA Device 5555 [...] > Initially, the BAR value is 0xb0400000. However, after some time, reading > from the PCIe device's BAR memory fails and returns 0xffff If you're reading "all ones" from config space, it means the device is inaccessible and the host bridge is returning this fabricated value after a timeout. > Kernel modules: m1801_pci That's not a driver in the upstream kernel. Maybe that driver allows the device to runtime suspend to D3hot, which in turn allows its upstream bridge to also runtime suspend to D3hot. Then the device would be inaccessible. > Verified power management settings: > > cat /sys/module/pcie_aspm/parameters/policy > Output: [default] performance powersave powersupersave /sys/bus/pci/devices/0000:01:00.0/power/runtime_status would tell you whether the device is runtime suspended. Thanks, Lukas