From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.bootlin.com ([62.4.15.54]:54009 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728109AbeJWALm (ORCPT ); Mon, 22 Oct 2018 20:11:42 -0400 Date: Mon, 22 Oct 2018 17:52:24 +0200 From: Alexandre Belloni To: Soeren Moch Cc: stable@vger.kernel.org, Andrea Greco , Alessandro Zummo , linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] rtc: ds1307: fix ds1339 wakealarm support Message-ID: <20181022155224.GS17341@piout.net> References: <20181022123812.5782-1-smoch@web.de> <20181022135757.GQ17341@piout.net> <3a6041a9-6fef-c113-5962-caa0a24aca49@web.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3a6041a9-6fef-c113-5962-caa0a24aca49@web.de> Sender: stable-owner@vger.kernel.org List-ID: On 22/10/2018 16:18:13+0200, Soeren Moch wrote: > Hi, > > Am 22.10.2018 um 15:57 schrieb Alexandre Belloni: > > Hello, > > > > On 22/10/2018 14:38:12+0200, Soeren Moch wrote: > >> Commit 51ed73eb998a1c79a2b0e9bed68f75a8a2c93b9b ("rtc: ds1340: Add support > >> for trickle charger.") breaks ds1339 wakealarm support by limiting > >> accessible registers. Fix this. > >> > >> Fixes: 51ed73eb998a ("rtc: ds1340: Add support for trickle charger.") > >> Cc: stable@vger.kernel.org > >> Signed-off-by: Soeren Moch > >> -- > >> Cc: Andrea Greco > >> Cc: Alessandro Zummo > >> Cc: Alexandre Belloni > >> Cc: linux-rtc@vger.kernel.org > >> Cc: linux-kernel@vger.kernel.org > >> --- > >> drivers/rtc/rtc-ds1307.c | 1 - > >> 1 file changed, 1 deletion(-) > >> > >> diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c > >> index 4b2b4627daeb..71396b62dc52 100644 > >> --- a/drivers/rtc/rtc-ds1307.c > >> +++ b/drivers/rtc/rtc-ds1307.c > >> @@ -1384,7 +1384,6 @@ static void ds1307_clks_register(struct ds1307 *ds1307) > >> static const struct regmap_config regmap_config = { > >> .reg_bits = 8, > >> .val_bits = 8, > >> - .max_register = 0x9, > > I would prefer having a different regmap_config for chips that have more > > registers. I guess you could put a pointer to a regmap_config in chip_desc. > > > What looks strange to me, the original patch (according to its > description) enabled trickle charger functionality for a single chip. > This is something totally different than limiting the register space for > all chips that are supported by this driver. So this seems to be an > accident to me. And this causes an regression for ds1339, which was > supported for years. > > Are there any advantages for limiting the address space of i2c devices? I would think it was done as a facility to debug the feature because when max_register is set, regmap will allow you to dump the register space. > If we really need this, can we apply this partial revert as regression > fix (also for stable) and implement the address space limitation separately? > Fine, I'm applying this patch right now. -- Alexandre Belloni, Bootlin Embedded Linux and Kernel engineering https://bootlin.com