Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752318AbbGUGHi (ORCPT ); Tue, 21 Jul 2015 02:07:38 -0400 Received: from mailgw02.mediatek.com ([210.61.82.184]:33024 "EHLO mailgw02.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1750837AbbGUGHg (ORCPT ); Tue, 21 Jul 2015 02:07:36 -0400 X-Listener-Flag: 11101 Message-ID: <1437458845.30329.51.camel@mtksdaap41> Subject: Re: [PATCH] regmap: Add function check before called format_val From: Henry Chen To: Mark Brown CC: Matthias Brugger , Sascha Hauer , , , , Date: Tue, 21 Jul 2015 14:07:25 +0800 In-Reply-To: <20150720150254.GC11162@sirena.org.uk> References: <1437396110-5192-1-git-send-email-henryc.chen@mediatek.com> <20150720150254.GC11162@sirena.org.uk> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 7bit MIME-Version: 1.0 X-MTK: N Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8992 Lines: 220 On Mon, 2015-07-20 at 16:02 +0100, Mark Brown wrote: > On Mon, Jul 20, 2015 at 08:41:50PM +0800, Henry Chen wrote: > > The regmap_format will not be initialize since regmap_bus is not assgined > > on regmap_init(). It should has a function check before using > > format_val() to avoid null function called on regmap_bulk_read(). > > > - map->format.format_val(val + (i * val_bytes), ival, 0); > > + if (map->format.format_val) > > + map->format.format_val(val + (i * val_bytes), ival, 0); > > + else > > + memcpy(val + (i * val_bytes), &ival, val_bytes); > > Your changelog doesn't explan why we are in this code path in the first > place without a format_val() and why a memcpy() is an appropriate > replacement. It should, it's not clear to me that this is a good fix > but I don't feel I fully understand the problem. Sorry for being unclear for issue, the call flow as following, First, in drivers/mfd/mtk_pmic_wrap.c which registered regmap without rebmap_bus. devm_regmap_init(wrp->dev, NULL, wrp, &pwrap_regmap_config); It call to regmap_init() and go to "skip_format_initialization" because regmap_bus didn't assign by driver. if (!bus) { map->reg_read = config->reg_read; map->reg_write = config->reg_write; map->defer_caching = false; goto skip_format_initialization;" Then in driver rtc-mt6397.c, it used regmap_bulk_read() to get the time of PMIC, and hit the null function of format_val(), because the regmap_bus was null. It skipped the initialization of format_val() because bus == null, but called the format_val() at regmap_bulk_read() if bus == null. Maybe it was not the good fix for this, but should be a problem need to be reported, or should I need to give the regmap_bus on mtk_pmic_wrap.c? I tested this on mediatek mt8173 evb platform. Please see the error below, thanks. Bad mode in Synchronous Abort handler detected, code 0x86000005 -- IABT (current EL) CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.2.0-rc1+ #25 Hardware name: MediaTek MT8173 evaluation board (DT) task: ffffffc077090000 ti: ffffffc07705c000 task.ti: ffffffc07705c000 PC is at 0x0 LR is at regmap_bulk_read+0x104/0x1c4 pc : [<0000000000000000>] lr : [] pstate: 20000045 sp : ffffffc07705fa00 x29: ffffffc07705fa00 x28: ffffffc0008ac970 x27: ffffffc0009530f8 x26: 0000000000000001 x25: 0000000000000001 x24: 000000000000e00a x23: ffffffc07705faa0 x22: 0000000000000002 x21: 0000000000000007 x20: ffffffc075ca8800 x19: 0000000000000001 x18: 0000000000000000 x17: 0000000000000001 x16: 0000000000000016 x15: 0000000000000cb0 x14: 0ffffffffffffffe x13: 0000000000000010 x12: 0000000000000001 x11: 0101010101010101 x10: 7f7f7f7f7f7f7f7f x9 : 6a6473606863646c x8 : 00000000ffffffd0 x7 : 0000000000000000 x6 : 0000000000000000 x5 : 00000000ffffffff x4 : 0000000000000000 x3 : 0000000000000000 x2 : 0000000000000000 x1 : 000000000000001c x0 : ffffffc07705faa0 Internal error: Oops - bad mode: 0 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.2.0-rc1+ #25 Hardware name: MediaTek MT8173 evaluation board (DT) task: ffffffc077090000 ti: ffffffc07705c000 task.ti: ffffffc07705c000 PC is at 0x0 LR is at regmap_bulk_read+0x104/0x1c4 pc : [<0000000000000000>] lr : [] pstate: 20000045 sp : ffffffc07705fa00 x29: ffffffc07705fa00 x28: ffffffc0008ac970 x27: ffffffc0009530f8 x26: 0000000000000001 x25: 0000000000000001 x24: 000000000000e00a x23: ffffffc07705faa0 x22: 0000000000000002 x21: 0000000000000007 x20: ffffffc075ca8800 x19: 0000000000000001 x18: 0000000000000000 x17: 0000000000000001 x16: 0000000000000016 x15: 0000000000000cb0 x14: 0ffffffffffffffe x13: 0000000000000010 x12: 0000000000000001 x11: 0101010101010101 x10: 7f7f7f7f7f7f7f7f x9 : 6a6473606863646c x8 : 00000000ffffffd0 x7 : 0000000000000000 x6 : 0000000000000000 x5 : 00000000ffffffff x4 : 0000000000000000 x3 : 0000000000000000 x2 : 0000000000000000 x1 : 000000000000001c x0 : ffffffc07705faa0 Process swapper/0 (pid: 1, stack limit = 0xffffffc07705c020) Stack: (0xffffffc07705fa00 to 0xffffffc077060000) fa00: 7705fa60 ffffffc0 004cbde4 ffffffc0 7705fb40 ffffffc0 762ead98 ffffffc0 fa20: 7705fb40 ffffffc0 762eada8 ffffffc0 7705fbf8 ffffffc0 007ca368 ffffffc0 fa40: 00908810 ffffffc0 004cbdcc ffffffc0 7705fb40 ffffffc0 0033a998 0000001c fa60: 7705fab0 ffffffc0 004c962c ffffffc0 7705fb40 ffffffc0 75c5aac8 ffffffc0 fa80: 7705fb40 ffffffc0 75c5aaac ffffffc0 75c5a810 ffffffc0 762ec800 ffffffc0 faa0: 00000000 00000000 75c5aaac ffffffc0 7705fad0 ffffffc0 004c969c ffffffc0 fac0: 75c5a800 ffffffc0 004c9688 ffffffc0 7705fb00 ffffffc0 004c9e78 ffffffc0 fae0: 75c5a800 ffffffc0 75ccf010 ffffffc0 75c5a800 ffffffc0 7705fb90 ffffffc0 fb00: 7705fb90 ffffffc0 004c8d40 ffffffc0 75c5a800 ffffffc0 75ccf010 ffffffc0 fb20: 00000000 00000000 75c5aaac ffffffc0 00953000 ffffffc0 007ca368 ffffffc0 fb40: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 fb60: 00000000 00000000 00006374 00000000 ffffffff ffffffff 80800000 80808080 fb80: 75c5aab6 ffffffc0 feff6273 fefefefe 7705fc20 ffffffc0 004cbf74 ffffffc0 fba0: 762ead98 ffffffc0 75ccf010 ffffffc0 00000000 00000000 007ca368 ffffffc0 fbc0: 008f9000 ffffffc0 00000000 00000000 00842264 ffffffc0 008766b0 ffffffc0 fbe0: 008766e0 ffffffc0 75ccf010 ffffffc0 75ccf000 ffffffc0 007ca368 ffffffc0 fc00: 008f9000 ffffffc0 00000000 00000000 00842264 ffffffc0 008766b0 ffffffc0 fc20: 7705fc50 ffffffc0 003fb5e4 ffffffc0 75ccf010 ffffffc0 00908760 ffffffc0 fc40: 00908788 ffffffc0 00950000 ffffffc0 7705fc80 ffffffc0 003f99e4 ffffffc0 fc60: 75ccf010 ffffffc0 00000000 00000000 00908788 ffffffc0 00950000 ffffffc0 fc80: 7705fcc0 ffffffc0 003f9b90 ffffffc0 75ccf010 ffffffc0 00908788 ffffffc0 fca0: 75ccf070 ffffffc0 008f9ac0 ffffffc0 008f9000 ffffffc0 00876740 ffffffc0 fcc0: 7705fcf0 ffffffc0 003f7ce4 ffffffc0 00000000 00000000 00908788 ffffffc0 fce0: 003f9af4 ffffffc0 00876740 ffffffc0 7705fd30 ffffffc0 003f94cc ffffffc0 fd00: 00908788 ffffffc0 76a3e3c0 ffffffc0 00000000 00000000 005f2380 ffffffc0 fd20: 77005ea8 ffffffc0 7725ade8 ffffffc0 7705fd40 ffffffc0 003f9168 ffffffc0 fd40: 7705fd80 ffffffc0 003fa460 ffffffc0 00908788 ffffffc0 008c8a60 ffffffc0 fd60: 00000000 00000000 00863990 ffffffc0 00000000 00000000 ffffffd0 00000000 fd80: 7705fdb0 ffffffc0 003fb518 ffffffc0 008c8a60 ffffffc0 008c8a60 ffffffc0 fda0: 762ec4c0 ffffffc0 00863990 ffffffc0 7705fdc0 ffffffc0 008639a8 ffffffc0 fdc0: 7705fdd0 ffffffc0 00082868 ffffffc0 7705fe50 ffffffc0 00842b14 ffffffc0 fde0: 000000bd 00000000 00930000 ffffffc0 008393d8 ffffffc0 00000006 00000000 fe00: 00930000 ffffffc0 008766b0 ffffffc0 00876600 ffffffc0 00000030 00000000 fe20: 7705fe30 ffffffc0 00793498 ffffffc0 00792d88 ffffffc0 00000006 00000006 fe40: 00000000 00000000 7e9fdbac ffffffc0 7705feb0 ffffffc0 005f43e0 ffffffc0 fe60: 005f43d0 ffffffc0 00000000 00000000 00000000 00000000 00000000 00000000 fe80: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 fea0: 00000000 00000000 00000000 00000000 00000000 00000000 00085c10 ffffffc0 fec0: 005f43d0 ffffffc0 00000000 00000000 00000000 00000000 00000000 00000000 fee0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 ff00: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 ff20: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 ff40: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 ff60: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 ff80: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 ffa0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 ffc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000005 00000000 ffe0: 00000000 00000000 00000000 00000000 0c2ae48d c2569cad c4144163 8cef60fe Call trace: [< (null)>] (null) [] mtk_rtc_read_time+0x9c/0x134 [] __rtc_read_time.isra.3+0x40/0x7c [] rtc_read_time+0x34/0x58 [] __rtc_read_alarm+0x20/0x37c [] rtc_device_register+0x194/0x2e0 [] mtk_rtc_probe+0xf8/0x18c [] platform_drv_probe+0x48/0xc4 [] driver_probe_device+0x188/0x29c [] __driver_attach+0x98/0xa0 [] bus_for_each_dev+0x54/0x98 [] driver_attach+0x1c/0x28 [] bus_add_driver+0x1c0/0x228 [] driver_register+0x64/0x130 [] __platform_driver_register+0x5c/0x68 [] mtk_rtc_driver_init+0x14/0x20 [] do_one_initcall+0x88/0x1ac [] kernel_init_freeable+0x158/0x1fc [] kernel_init+0xc/0xd8 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/