Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753687AbaDCUkY (ORCPT ); Thu, 3 Apr 2014 16:40:24 -0400 Received: from mail-qa0-f51.google.com ([209.85.216.51]:56766 "EHLO mail-qa0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753497AbaDCUkR (ORCPT ); Thu, 3 Apr 2014 16:40:17 -0400 MIME-Version: 1.0 In-Reply-To: References: <1395179766-31575-1-git-send-email-pantelis.antoniou@konsulko.com> Date: Thu, 3 Apr 2014 15:40:16 -0500 Message-ID: Subject: Re: [PATCH v3 0/7] Introducing (yet again) Device Tree Overlays From: delicious quinoa To: Pantelis Antoniou Cc: Grant Likely , Rob Herring , Stephen Warren , Matt Porter , Koen Kooi , Alison Chaiken , Dinh Nguyen , Jan Lubbe , Alexander Sverdlin , Michael Stickel , Guenter Roeck , Dirk Behme , Sascha Hauer , Michael Bohan , Ionut Nicu , Michal Simek , Matt Ranostay , "devicetree@vger.kernel.org" , linux-kernel , Pete Popov , Dan Malek , Georgi Vlaev Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 28, 2014 at 1:27 PM, delicious quinoa wrote: > On Tue, Mar 18, 2014 at 4:55 PM, Pantelis Antoniou > wrote: >> The following patchset introduces Device Tree overlays, a method >> of dynamically altering the kernel's live Device Tree, along with >> a generic interface to use it in a board agnostic manner. >> >> It is dependent on Grant Likely's DT kobjectification patches located >> in his tree as queued for -next. >> >> It relies on the following previously submitted patches/patchsets: >> >> * OF: Add [__]of_find_node_by_full_name >> * OF: Utility helper functions for dynamic nodes >> * of: Make of_find_node_by_path() handle /aliases >> >> To compile overlays you need the DTC compiler patch >> >> * "dtc: Dynamic symbols & fixup support (v2)" >> >> Changes since V2: >> * Use of a configfs board agnostic overlay method >> * Use of per bus handlers instead of hardcoded behaviour >> * Optional target-path overlay target, which allows one to use standard >> DTBs without resolution options. >> >> Changes since V1: >> >> * Removal of any bits related to a specific board (beaglebone). >> * Introduced a platform agnostic interface using /proc/device-tree-overlay >> * Various bug fixes related to i2c device handling have been squashed in. >> >> >> Pantelis Antoniou (7): >> OF: Introduce Device Tree resolve support. >> OF: Introduce DT overlay support. >> OF: DT-Overlay configfs interface >> OF: platform: Add overlay bus handler >> OF: i2c: Add overlay bus handler >> OF: spi: Add overlay bus handler >> of: i2c: Export single device registration method >> >> .../devicetree/dynamic-resolution-notes.txt | 25 + >> Documentation/devicetree/overlay-notes.txt | 187 +++++ >> drivers/base/platform.c | 99 ++- >> drivers/i2c/i2c-core.c | 186 +++-- >> drivers/of/Kconfig | 24 + >> drivers/of/Makefile | 3 + >> drivers/of/configfs.c | 272 +++++++ >> drivers/of/overlay.c | 895 +++++++++++++++++++++ >> drivers/of/resolver.c | 376 +++++++++ >> drivers/spi/spi.c | 345 +++++--- >> include/linux/i2c.h | 10 + >> include/linux/of.h | 170 ++++ >> 12 files changed, 2440 insertions(+), 152 deletions(-) >> create mode 100644 Documentation/devicetree/dynamic-resolution-notes.txt >> create mode 100644 Documentation/devicetree/overlay-notes.txt >> create mode 100644 drivers/of/configfs.c >> create mode 100644 drivers/of/overlay.c >> create mode 100644 drivers/of/resolver.c > > I can get a NULL pointer when I apply and remove an overlay and the > conditions are right. The overlay applies correctly. The crash is > when I do the rmdir. My overlay is: > > /dts-v1/; > /plugin/; > / { > fragment@0 { > target-path="/soc"; > __overlay__ { > #address-cells = <1>; > #size-cells = <1>; > agpio0: agpio0 { > compatible = "altr,pio-1.0"; > reg = <0xff210040 0x10>; Added some printks and got a bit further with debug. If I leave this as-is, the platform device has 2 resources. We get the NULL pointer in __release_resource() when releasing the first one (reg). If I remove this one line ('reg =') the crash goes away. So in this case, we are ok when releasing an irq resource but get a NULL pointer when removing a reg resource. Don't know why at this point. > interrupts = <0 45 4>; > altr,gpio-bank-width = <32>; > altr,interrupt_type = <1>; > #gpio-cells = <2>; > gpio-controller; > #interrupt-cells = <1>; > interrupt-controller; > }; > }; > }; > }; > > The log info I have is: > > root@socfpga_cyclone5:~# ./do-overlay-only > + mkdir /config/device-tree/overlays/foo > + echo socfpga_overlay.dtbo > + rmdir /config/device-tree/overlays/foo > Unable to handle kernel NULL pointer dereference at virtual address 00000018 > pgd = bf164000 > [00000018] *pgd=3fb9c831, *pte=00000000, *ppte=00000000 > Internal error: Oops: 17 [#1] SMP ARM > Modules linked in: > CPU: 1 PID: 175 Comm: rmdir Not tainted 3.13.0-00299-g2e61581 #7 > task: bf00f400 ti: bfba4000 task.ti: bfba4000 > PC is at release_resource+0x24/0x98 > LR is at release_resource+0x20/0x98 > pc : [<800286e0>] lr : [<800286dc>] psr: 60000013 > sp : bfba5da0 ip : bfba5da0 fp : bfba5db4 > r10: 00100100 r9 : 00000000 r8 : 00200200 > r7 : 80732ff8 r6 : 00000001 r5 : bfbb8400 r4 : bfbd1100 > r3 : 00000000 r2 : 00000000 r1 : 00000002 r0 : 8074e580 > Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user > Control: 10c5387d Table: 3f16404a DAC: 00000015 > Process rmdir (pid: 175, stack limit = 0xbfba4248) > Stack: (0xbfba5da0 to 0xbfba6000) > 5da0: 00000000 00000001 bfba5dcc bfba5db8 802f2e40 800286c8 bfbb8400 bfb930c0 > 5dc0: bfba5de4 bfba5dd0 802f31e0 802f2dd0 bfbb8434 bfbb8400 bfba5dfc bfba5de8 > 5de0: 802f3224 802f31d0 802f31ec 807410ac bfba5e24 bfba5e00 803b4f20 802f31f8 > 5e00: bfb930c0 bfbe61a8 bfbe61a8 bfbe6180 00200200 00100100 bfba5e4c bfba5e28 > 5e20: 803b4fec 803b4e68 bfbe6140 ffffffff bfbe6188 00000000 80782dd4 80741108 > 5e40: bfba5e6c bfba5e50 803b51ec 803b4f94 00001040 bf82e000 807410b4 00000000 > 5e60: bfba5e84 bfba5e70 803b57f0 803b51b4 803b5778 bf82e018 bfba5ea4 bfba5e88 > 5e80: 80161df8 803b5784 00000000 00000000 bf82e000 bfb26070 bfba5eb4 bfba5ea8 > 5ea0: 80161e64 80161d9c bfba5eec bfba5eb8 8016071c 80161e28 80110da0 8010efbc > 5ec0: bf59a198 bf59a198 00000000 bf5543f0 7e96ef14 ffffff9c bfba4000 bf59a198 > 5ee0: bfba5f0c bfba5ef0 801086e4 8016054c bf5533b8 bf128000 00000000 00000000 > 5f00: bfba5f94 bfba5f10 80108870 80108650 bf8e3010 bf5533b8 006f6f66 00000003 > 5f20: bf12802d 80107348 00000000 bf576660 bf5543f0 00000000 00000004 00000060 > 5f40: 00000000 00000000 bfba5f64 bfba5f58 800fcb1c 8003f114 bfba5f84 bfba5f68 > 5f60: 8003f114 804d1630 bfba4000 bfba4000 7e96ef14 00000000 7e96ee28 00000028 > 5f80: 8000ece4 00000000 bfba5fa4 bfba5f98 8010a800 8010875c 00000000 bfba5fa8 > 5fa0: 8000eac0 8010a7ec 7e96ef14 00000000 7e96ef14 00000000 00000002 7e96ee28 > 5fc0: 7e96ef14 00000000 7e96ee28 00000028 00000002 7e96ee24 0006a754 00000000 > 5fe0: 76f3d450 7e96ec74 0003c2e5 76f3d45c 80000010 7e96ef14 00000000 00000000 > [<800286e0>] (release_resource+0x24/0x98) from [<802f2e40>] > (platform_device_del+0x7c/0xac) > [<802f2e40>] (platform_device_del+0x7c/0xac) from [<802f31e0>] > (platform_device_unregister+0x1c/0x28) > [<802f31e0>] (platform_device_unregister+0x1c/0x28) from [<802f3224>] > (platform_handler_remove+0x38/0x54) > [<802f3224>] (platform_handler_remove+0x38/0x54) from [<803b4f20>] > (of_overlay_device_entry_change.isra.0+0xc4/0x12c) > [<803b4f20>] (of_overlay_device_entry_change.isra.0+0xc4/0x12c) from > [<803b4fec>] (of_overlay_revert_one+0x64/0x220) > [<803b4fec>] (of_overlay_revert_one+0x64/0x220) from [<803b51ec>] > (of_overlay_revert+0x44/0x64) > [<803b51ec>] (of_overlay_revert+0x44/0x64) from [<803b57f0>] > (cfs_overlay_release+0x78/0x7c) > [<803b57f0>] (cfs_overlay_release+0x78/0x7c) from [<80161df8>] > (config_item_release+0x68/0x8c) > [<80161df8>] (config_item_release+0x68/0x8c) from [<80161e64>] > (config_item_put+0x48/0x4c) > [<80161e64>] (config_item_put+0x48/0x4c) from [<8016071c>] > (configfs_rmdir+0x1dc/0x264) > [<8016071c>] (configfs_rmdir+0x1dc/0x264) from [<801086e4>] > (vfs_rmdir+0xa0/0x10c) > [<801086e4>] (vfs_rmdir+0xa0/0x10c) from [<80108870>] (do_rmdir+0x120/0x150) > [<80108870>] (do_rmdir+0x120/0x150) from [<8010a800>] (SyS_rmdir+0x20/0x24) > [<8010a800>] (SyS_rmdir+0x20/0x24) from [<8000eac0>] (ret_fast_syscall+0x0/0x30) > Code: e1a04000 e59f0074 eb12b02b e5943010 (e5932018) > ---[ end trace 1b8539e83d8e0ecc ]--- > ./do-overlay-only: line 7: 175 Segmentation fault rmdir > /config/device-tree/overlays/foo > root@socfpga_cyclone5:~# > > I did some debug, haven't figured anything out yet. > > I have been able to successfully add/remove an overlay if it was to a > fpga node that was at /fpga and used 'target = <&fpga>;' Also > 'target-path="/fpga";' works fine. > > Alan Tull > aka > delicious quinoa -- 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/