On Mon, Jun 07, 2021 at 12:09:10PM +0100, Jon Hunter wrote: > > On 04/06/2021 11:00, Bartosz Golaszewski wrote: > > On Wed, Jun 2, 2021 at 7:08 PM Alexander Fomichev <fomichev.ru@xxxxxxxxx> wrote: > > ... > > >> This change has a serious defect, as it doesn't guarantee a name > >> uniqueness. For my case there are a bunch of NVMEM devices with > >> 'dimm-spd' name. So the module initialization fails with several error > >> dumps in dmesg, like following: > >> > >> [ 4.784679] at24 3-0051: supply vcc not found, using dummy regulator > >> [ 4.784781] sysfs: cannot create duplicate filename '/bus/nvmem/devices/dimm-spd' > >> [ 4.784783] CPU: 24 PID: 1354 Comm: systemd-udevd Not tainted 5.13.0-rc4-at24-catch+ #25 > >> [ 4.784787] Call Trace: > >> [ 4.784789] [c00000003f3eb010] [c000000000914700] dump_stack+0xc4/0x114 (unreliable) > >> [ 4.784797] [c00000003f3eb060] [c00000000061c5c8] sysfs_warn_dup+0x88/0xc0 > >> [ 4.784803] [c00000003f3eb0e0] [c00000000061ccec] sysfs_do_create_link_sd+0x17c/0x190 > >> [ 4.784809] [c00000003f3eb130] [c000000000ac3014] bus_add_device+0x94/0x1d0 > >> [ 4.784817] [c00000003f3eb1b0] [c000000000abe7b8] device_add+0x428/0xb90 > >> [ 4.784822] [c00000003f3eb2a0] [c000000000debbd0] nvmem_register+0x220/0xe00 > >> [ 4.784829] [c00000003f3eb390] [c000000000dec80c] devm_nvmem_register+0x5c/0xc0 > >> [ 4.784835] [c00000003f3eb3d0] [c008000016f40c20] at24_probe+0x668/0x940 [at24] > >> [ 4.784845] [c00000003f3eb650] [c000000000cfecd4] i2c_device_probe+0x194/0x650 > >> [ 4.784850] [c00000003f3eb6f0] [c000000000ac4d3c] really_probe+0x1cc/0x790 > >> [ 4.784855] [c00000003f3eb790] [c000000000ac545c] driver_probe_device+0x15c/0x200 > >> [ 4.784861] [c00000003f3eb810] [c000000000ac5ecc] device_driver_attach+0x11c/0x130 > >> [ 4.784866] [c00000003f3eb850] [c000000000ac5fd0] __driver_attach+0xf0/0x200 > >> [ 4.784873] [c00000003f3eb8d0] [c000000000ac1158] bus_for_each_dev+0xa8/0x130 > >> [ 4.784879] [c00000003f3eb930] [c000000000ac4104] driver_attach+0x34/0x50 > >> [ 4.784885] [c00000003f3eb950] [c000000000ac35f0] bus_add_driver+0x1b0/0x2f0 > >> [ 4.784893] [c00000003f3eb9e0] [c000000000ac70b4] driver_register+0xb4/0x1c0 > >> [ 4.784900] [c00000003f3eba50] [c000000000cfe498] i2c_register_driver+0x78/0x120 > >> [ 4.784905] [c00000003f3ebad0] [c008000016f41260] at24_init+0x6c/0x88 [at24] > >> [ 4.784914] [c00000003f3ebb30] [c0000000000122c0] do_one_initcall+0x60/0x2c0 > >> [ 4.784920] [c00000003f3ebc00] [c0000000002537bc] do_init_module+0x7c/0x350 > >> [ 4.784926] [c00000003f3ebc90] [c000000000257904] __do_sys_finit_module+0xd4/0x160 > >> [ 4.784932] [c00000003f3ebdb0] [c00000000002c104] system_call_exception+0xf4/0x200 > >> [ 4.784938] [c00000003f3ebe10] [c00000000000cf70] system_call_vectored_common+0xf0/0x268 > >> [ 4.784944] --- interrupt: 3000 at 0x7c1adac4b4c4 > >> [ 4.784948] NIP: 00007c1adac4b4c4 LR: 0000000000000000 CTR: 0000000000000000 > >> [ 4.784951] REGS: c00000003f3ebe80 TRAP: 3000 Not tainted (5.13.0-rc4-at24-catch+) > >> [ 4.784955] MSR: 900000000280f033 <SF,HV,VEC,VSX,EE,PR,FP,ME,IR,DR,RI,LE> CR: 48222844 XER: 00000000 > >> [ 4.784976] IRQMASK: 0 > >> GPR00: 0000000000000161 00007fffefc78b90 00007c1adad37000 0000000000000006 > >> GPR04: 00000f6614d56be0 0000000000000000 0000000000000006 0000000000000000 > >> GPR08: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 > >> GPR12: 0000000000000000 00007c1adafde680 0000000020000000 0000000000000000 > >> GPR16: 0000000000000000 00000f66118b1980 00000f66118b1a18 00000f66118b1948 > >> GPR20: 0000000000000000 00000f6614d60500 00007fffefc78df0 00000f6614d535c0 > >> GPR24: 00000f6614d56be0 00000f6614d60500 000000000000000c 00000f6614d49cb0 > >> GPR28: 00000f6614d56be0 0000000000020000 0000000000000000 00000f6614d60500 > >> [ 4.785033] NIP [00007c1adac4b4c4] 0x7c1adac4b4c4 > >> [ 4.785036] LR [0000000000000000] 0x0 > >> [ 4.785040] --- interrupt: 3000 > >> [ 4.785146] at24: probe of 3-0051 failed with error -17 > >> > >> > >> It needs either to use NVMEM_DEVID_AUTO flag irrespective of the 'label' > >> property or to add a sort of counter suffix to the name field. > >> > >> > >> Reported-by: Alexander Fomichev <fomichev.ru@xxxxxxxxx> > >> CC: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx> > >> > >> -- > >> Regards, > >> Alexander > > > > Alexander: Thanks for your bug report. The counter suffix you suggest > > is precisely what NVMEM_DEVID_AUTO would do so I think we'll need to > > use it. On the other hand, a non-unique label is bad design but > > obviously we can't break working setups. > > Yes the intention was that the label itself would be unique. In our case > we wanted to have something specifically named 'system' or 'module' to > identify a specific eeprom. > > BTW I did a quick grep from 'dimm-spd' and did not find it in the > kernel. Where is the device-tree you are using? > > > Jon: As the author of this patch - do you have any objections/better ideas? > > I would need to check if appending a suffix then has ramifications for > what we were trying to achieve. > On POWER8/POWER9 platforms (affected by this issue) the devicetree is built on-the-boot by firmware. Here are labels of the current eeprom/nvmem devices: $ l=$(find /sys/firmware/devicetree/base/xscom@603fc00000000/ -name label); for i in `echo "$l"`; do echo $i ':'; cat $i; echo; done /sys/firmware/devicetree/base/xscom@603fc00000000/i2cm@a1000/i2c-bus@2/eeprom@50/label : module-vpd /sys/firmware/devicetree/base/xscom@603fc00000000/i2cm@a1000/i2c-bus@0/eeprom@50/label : module-vpd /sys/firmware/devicetree/base/xscom@603fc00000000/i2cm@a3000/i2c-bus@0/eeprom@52/label : dimm-spd /sys/firmware/devicetree/base/xscom@603fc00000000/i2cm@a3000/i2c-bus@0/eeprom@50/label : dimm-spd /sys/firmware/devicetree/base/xscom@603fc00000000/i2cm@a3000/i2c-bus@0/eeprom@53/label : dimm-spd /sys/firmware/devicetree/base/xscom@603fc00000000/i2cm@a3000/i2c-bus@0/eeprom@51/label : dimm-spd /sys/firmware/devicetree/base/xscom@603fc00000000/i2cm@a3000/i2c-bus@1/eeprom@54/label : dimm-spd /sys/firmware/devicetree/base/xscom@603fc00000000/i2cm@a3000/i2c-bus@1/eeprom@57/label : dimm-spd /sys/firmware/devicetree/base/xscom@603fc00000000/i2cm@a3000/i2c-bus@1/eeprom@55/label : dimm-spd /sys/firmware/devicetree/base/xscom@603fc00000000/i2cm@a3000/i2c-bus@1/eeprom@56/label : dimm-spd /sys/firmware/devicetree/base/xscom@603fc00000000/i2cm@a2000/i2c-bus@0/eeprom@50/label : system-vpd There are two 'module-vpd' labels and multiple 'dimm-spd' labels. Even more can exist. Possible devicetree template, used by OpenPower Firmware: https://raw.githubusercontent.com/open-power/nicole-xml/master/nicole.xml So this is not a MUST for label to be unique. -- Regards, Alexander
