From: Bastien Nocera Subject: Disabling PM fixes Wi-Fi stability Date: Fri, 12 Dec 2014 11:51:33 +0100 Message-ID: <1418381493.3172.26.camel@hadess.net> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: Received: from relay6-d.mail.gandi.net ([217.70.183.198]:38816 "EHLO relay6-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966102AbaLLKwg (ORCPT ); Fri, 12 Dec 2014 05:52:36 -0500 Received: from mfilter37-d.gandi.net (mfilter37-d.gandi.net [217.70.178.168]) by relay6-d.mail.gandi.net (Postfix) with ESMTP id 4E2E8FB89E for ; Fri, 12 Dec 2014 11:52:35 +0100 (CET) Received: from relay6-d.mail.gandi.net ([217.70.183.198]) by mfilter37-d.gandi.net (mfilter37-d.gandi.net [10.0.15.180]) (amavisd-new, port 10024) with ESMTP id in4isYmNlkfq for ; Fri, 12 Dec 2014 11:52:33 +0100 (CET) Received: from nuvo (mon69-7-83-155-44-161.fbx.proxad.net [83.155.44.161]) (Authenticated sender: hadess@hadess.net) by relay6-d.mail.gandi.net (Postfix) with ESMTPSA id CCB05FB8A4 for ; Fri, 12 Dec 2014 11:52:33 +0100 (CET) Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: linux-mmc@vger.kernel.org Hey, On my Onda v975w tablet[1], using a non-upstreamed Realtek driver[2], I used to have the tablet hang after using Wi-Fi for a couple of minutes. I unfortunately couldn't get any stacktraces of the hang. I suspected Power Management in the SDHCI-ACPI driver to be a problem, as the Wi-Fi chipset hangs off SDIO. Using this horror of a patch: https://gist.github.com/hadess/6ce1b1c5dc8f5468d9dc Wi-Fi becomes stable enough to be used. Is this an SDHCI bug? an ACPI bug? A driver bug? If the machine was a desktop, I probably wouldn't care much about the lack of Power Management, but on a tablet... Cheers [1]: A Baytrail tablet https://wiki.gnome.org/BastienNocera/Ondav975w [2]: https://github.com/hadess/rtl8723as