From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760226AbcHaUoO (ORCPT ); Wed, 31 Aug 2016 16:44:14 -0400 Received: from mail-wm0-f67.google.com ([74.125.82.67]:33692 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753198AbcHaUoM (ORCPT ); Wed, 31 Aug 2016 16:44:12 -0400 MIME-Version: 1.0 In-Reply-To: <1472675395.5025.31.camel@intel.com> References: <1472596930.23886.13.camel@intel.com> <1472674733.5025.28.camel@intel.com> <1472675395.5025.31.camel@intel.com> From: Matt Ranostay Date: Wed, 31 Aug 2016 13:43:29 -0700 Message-ID: Subject: Re: screen rotation flipped in 4.8-rc To: "Pandruvada, Srinivas" Cc: "linux-kernel@vger.kernel.org" , "linux@sciencehorizons.net" , "linux-iio@vger.kernel.org" , "jic23@kernel.org" , "hadess@hadess.net" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 31, 2016 at 1:29 PM, Pandruvada, Srinivas wrote: > On Wed, 2016-08-31 at 13:24 -0700, Matt Ranostay wrote: >> On Wed, Aug 31, 2016 at 1:18 PM, Pandruvada, Srinivas >> wrote: >> > >> > On Tue, 2016-08-30 at 17:41 -0700, Matt Ranostay wrote: >> > > >> > > On Tue, Aug 30, 2016 at 3:42 PM, Pandruvada, Srinivas >> > > wrote: >> > > > >> > > > >> > > > Hi All, >> > > > >> > > > I observed that using iio-sensor-proxy.service, the auto screen >> > > > rotation flipped on my laptop (Normal -> vertical, vertical- >> > > > > >> > > > > normal) >> > > > using kernel v4.8. >> > > > >> > > > Anyone else has seen this? >> > > > >> > > > I did a bisect and found a commit, which I am not sure how can >> > > > it >> > > > impact. >> > > Could you post the results of CONFIG_TEST_HASH enabled? >> > Attached dmesg.txt with the CONFIG_TEST_HASH=y. >> > >> > I see >> > [ 4.276138] test_hash: __hash_32() has no arch implementation to >> > test. >> > [ 4.276138] test_hash: hash_32() has no arch implementation to >> > test. >> > [ 4.276139] test_hash: hash_64() has no arch implementation to >> > test. >> > [ 4.276141] test_hash: 33152 tests passed. >> > >> Ok have you tested with that patchset reverted? And if so does the >> regression disappear? > Yes, but not after adding CONFIG_TEST_HASH=y. > regression disappears. > >> I would highly doubt if it was a issue with that dcache patchsets it >> wouldn't be breaking a ton of things. > I also think that. Only thing I could suspect is a toolchain bug.. Have crazy idea for you to try below.. >>From the patchset notice the return doesn't cast the result to (unsigned int) as before. But __hash_32_generic is "static inline u32", and maybe the end_name_hash is returning the whole result as a 64-bit unsigned long rather than 32-bit unsigned int. .... static inline unsigned long end_name_hash(unsigned long hash) { - return (unsigned int)hash; + return __hash_32((unsigned int)hash); } .... Just a theory.. Could totally be wrong :). > > Thanks, > Srinivas > >> >> > >> > Thanks, >> > Srinivas >> > > >> > > >> > > Thanks, >> > > >> > > Matt >> > > >> > > > >> > > > >> > > > >> > > > >> > > > commit 703b5faf22fbddf984a361e6555f3a03fdba63d9 >> > > > Author: George Spelvin >> > > > Date: Fri Jun 10 00:22:12 2016 -0400 >> > > > >> > > > fs/dcache.c: Save one 32-bit multiply in dcache lookup >> > > > >> > > > Noe that we're mixing in the parent pointer earlier, we >> > > > don't need to use hash_32() to mix its bits. Instead, we >> > > > can >> > > > just take the msbits of the hash value directly. >> > > > >> > > > For those applications which use the partial_name_hash(), >> > > > move the multiply to end_name_hash. >> > > > >> > > > Signed-off-by: George Spelvin >> > > > Signed-off-by: Linus Torvalds > > > > g> >> > > > >> > > > >> > > > Thanks, >> > > > Srinivas