From mboxrd@z Thu Jan 1 00:00:00 1970 From: josh@joshtriplett.org Subject: Re: [PATCH] x86/efi-bgrt: Switch pr_err() to pr_debug() for invalid BGRT Date: Mon, 29 Jun 2015 09:35:53 -0700 Message-ID: <20150629163553.GB1348@cloud> References: <1435579602-6612-1-git-send-email-matt@codeblueprint.co.uk> <20150629131305.GB13113@pd.tnic> <20150629140022.GA22374@x> <20150629141724.GG12383@pd.tnic> <20150629144940.GF28334@codeblueprint.co.uk> <20150629154458.GH12383@pd.tnic> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from relay4-d.mail.gandi.net ([217.70.183.196]:42404 "EHLO relay4-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751385AbbF2Qf5 (ORCPT ); Mon, 29 Jun 2015 12:35:57 -0400 Content-Disposition: inline In-Reply-To: <20150629154458.GH12383@pd.tnic> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Borislav Petkov Cc: Matt Fleming , Tom Yan , Matthew Garrett , linux-efi@vger.kernel.org, linux-acpi@vger.kernel.org, Matt Fleming On Mon, Jun 29, 2015 at 05:44:58PM +0200, Borislav Petkov wrote: > On Mon, Jun 29, 2015 at 03:49:40PM +0100, Matt Fleming wrote: > > It still makes sense to have the error message because the kernel > > literally does not know what the firmware is trying to achieve by > > setting those bits. > > > > But I agree with Josh that for the specific case of "reserved bits", > > FW_BUG is wrong, because if in some future version of the spec those > > bits get used, seeing, > > > > "[Firmware Bug]: Ignoring BGRT: reserved bits are non-zero 0x3" > > I still don't see what that message brings if some kernel complains that > some bits are !0 then. Are they valid bits which the kernel doesn't know > about or are they erroneously set and reserved. This, IMHO, is confusing > because the error message is not correct in all cases. > > Thus my suggestion to either check the spec version before looking at > the bits or find out in some other way which bits are defined and which > are reserved and warn only about the reserved ones which are 1b. The version is already checked *before* the status bits: if the version is not 1, the kernel stops there and ignores the BGRT, before printing a message about status. - Josh Triplett