Re: [PATCH] nvmem: rmem: Make reserved region name unique

From: Stefan Wahren
Date: Tue Apr 11 2023 - 12:59:19 EST


Hi Ivan,

Am 11.04.23 um 15:50 schrieb Ivan T. Ivanov:
They could be multiple reserved memory regions,
so let's make their names unique.

This fixes following kernel error:

[ 9.831285] sysfs: cannot create duplicate filename '/bus/nvmem/devices/rmem0'

could you please provide more background information:

- are two instances of rmem trying to create this file?
- which exact platform is affect (Raspberry Pi 4), because the Hardware name from the trace is useless?
- could you provide some reliable scenario/config to reproduce this issue?

[ 9.831304] CPU: 3 PID: 467 Comm: (udev-worker) Not tainted 6.2.9-1-default #1 openSUSE Tumbleweed a4aeb3a90c0f23041a8a7944b12739b07585f009
[ 9.831326] Hardware name: raspberrypi rpi/rpi, BIOS 2023.01 01/01/2023
[ 9.831335] Call trace:
[ 9.831343] dump_backtrace+0xe4/0x140
[ 9.831366] show_stack+0x20/0x30
[ 9.831379] dump_stack_lvl+0x64/0x80
[ 9.831398] dump_stack+0x18/0x34
[ 9.831410] sysfs_warn_dup+0x6c/0x90
[ 9.831424] sysfs_do_create_link_sd+0xf8/0x100
[ 9.831437] sysfs_create_link+0x28/0x50
[ 9.831449] bus_add_device+0x70/0x190
[ 9.831468] device_add+0x3e8/0x84c
[ 9.831481] nvmem_register+0x85c/0x9f0
[ 9.831500] devm_nvmem_register+0x24/0x70
[ 9.831517] rmem_probe+0xa0/0xf4 [nvmem_rmem 649243b01e5e28ee94e4dd53bd13b6ececa836f8]
[ 9.831555] platform_probe+0x70/0xd0
[ 9.831566] really_probe+0xc8/0x3e4
[ 9.831582] __driver_probe_device+0x84/0x190
[ 9.831598] driver_probe_device+0x44/0x11c
[ 9.831613] __driver_attach+0xf8/0x200
[ 9.831629] bus_for_each_dev+0x78/0xd0
[ 9.831643] driver_attach+0x2c/0x40
[ 9.831657] bus_add_driver+0x188/0x250
[ 9.831672] driver_register+0x80/0x13c
[ 9.831688] __platform_driver_register+0x30/0x40
[ 9.831699] rmem_driver_init+0x28/0x1000 [nvmem_rmem 649243b01e5e28ee94e4dd53bd13b6ececa836f8]
[ 9.831727] do_one_initcall+0x48/0x2bc
[ 9.831740] do_init_module+0x50/0x1f0
[ 9.831753] load_module+0x1e54/0x2250
[ 9.831763] __do_sys_init_module+0x2ac/0x2f0
[ 9.831774] __arm64_sys_init_module+0x24/0x30
[ 9.831785] invoke_syscall+0x78/0x100
[ 9.831803] el0_svc_common.constprop.0+0x15c/0x180
[ 9.831820] do_el0_svc+0x40/0xb0
[ 9.831836] el0_svc+0x34/0x134
[ 9.831850] el0t_64_sync_handler+0x114/0x120
[ 9.831865] el0t_64_sync+0x1a4/0x1a8
[ 9.831956] rmem: probe of 3ef62ce0.nvram failed with error -17

Some background information about the issue could be found here:
https://bugzilla.suse.com/show_bug.cgi?id=1206846

Signed-off-by: Ivan T. Ivanov <iivanov@xxxxxxx>
---
drivers/nvmem/rmem.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/nvmem/rmem.c b/drivers/nvmem/rmem.c
index 80cb187f1481..77c70a47d519 100644
--- a/drivers/nvmem/rmem.c
+++ b/drivers/nvmem/rmem.c
@@ -70,7 +70,7 @@ static int rmem_probe(struct platform_device *pdev)
config.dev = dev;
config.priv = priv;
- config.name = "rmem";
+ config.name = dev_name(dev);

AFAIR changing userspace isn't great because application could rely on the filename prefix.

What is the result after applying this patch:

ls bus/nvmem/devices/rmem*

config.size = mem->size;
config.reg_read = rmem_read;