On Tue, Mar 18, 2014 at 4:55 PM, Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx> 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>; 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 devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html