mtd: Use mtd device name instead of mtd->name when registering nvmem device

[Christophe Kerello]

MTD currently allows to have same partition name on different devices.
Since nvmen device registration has been added, it is not more possible
to have same partition name on different devices. We get following
logs:
sysfs: cannot create duplicate filename XXX
Failed to register NVMEM device

To avoid such issue, the proposed patch uses the mtd device name instead of
the partition name.

Fixes: c4dfa25ab307 ("mtd: add support for reading MTD devices via the nvmem API")
Signed-off-by: Christophe Kerello <christophe.kerello@xxxxxx>
---
Hi,

With latest mtd-next branch, we get following logs on our STM32MP1 eval board.

[    1.979089] nand: device found, Manufacturer ID: 0x2c, Chip ID: 0xd3
[    1.984055] nand: Micron MT29F8G08ABACAH4
[    1.988000] nand: 1024 MiB, SLC, erase size: 256 KiB, page size: 4096, OOB size: 224
[    1.996378] Bad block table found at page 262080, version 0x01
[    2.001945] Bad block table found at page 262016, version 0x01
[    2.008002] 4 fixed-partitions partitions found on MTD device 58002000.nand-controller
[    2.015398] Creating 4 MTD partitions on "58002000.nand-controller":
[    2.021751] 0x000000000000-0x000000200000 : "fsbl"
[    2.028506] 0x000000200000-0x000000400000 : "ssbl1"
[    2.033741] 0x000000400000-0x000000600000 : "ssbl2"
[    2.038924] 0x000000600000-0x000040000000 : "UBI"
[    2.051336] spi-nor spi0.0: mx66l51235l (65536 Kbytes)
[    2.055123] 4 fixed-partitions partitions found on MTD device spi0.0
[    2.061378] Creating 4 MTD partitions on "spi0.0":
[    2.066243] 0x000000000000-0x000000040000 : "fsbl"
[    2.071429] sysfs: cannot create duplicate filename '/bus/nvmem/devices/fsbl'
[    2.078157] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.4.0-rc4-00031-g589e1b6 #176
[    2.085781] Hardware name: STM32 (Device Tree Support)
[    2.090957] [<c0312830>] (unwind_backtrace) from [<c030cbe4>] (show_stack+0x10/0x14)
[    2.098693] [<c030cbe4>] (show_stack) from [<c0e8d340>] (dump_stack+0xb4/0xc8)
[    2.105929] [<c0e8d340>] (dump_stack) from [<c050fcdc>] (sysfs_warn_dup+0x58/0x64)
[    2.113509] [<c050fcdc>] (sysfs_warn_dup) from [<c0510010>] (sysfs_do_create_link_sd+0xe4/0xe8)
[    2.122224] [<c0510010>] (sysfs_do_create_link_sd) from [<c0956f60>] (bus_add_device+0x80/0xfc)
[    2.130938] [<c0956f60>] (bus_add_device) from [<c0953f54>] (device_add+0x35c/0x608)
[    2.138697] [<c0953f54>] (device_add) from [<c0d12e0c>] (nvmem_register.part.2+0x180/0x624)
[    2.147065] [<c0d12e0c>] (nvmem_register.part.2) from [<c09ea5c8>] (add_mtd_device+0x2d8/0x4b8)
[    2.155776] [<c09ea5c8>] (add_mtd_device) from [<c09edbd4>] (add_mtd_partitions+0x84/0x16c)
[    2.164140] [<c09edbd4>] (add_mtd_partitions) from [<c09ed9ac>] (parse_mtd_partitions+0x220/0x3c4)
[    2.173118] [<c09ed9ac>] (parse_mtd_partitions) from [<c09ea8d4>] (mtd_device_parse_register+0x40/0x164)
[    2.182622] [<c09ea8d4>] (mtd_device_parse_register) from [<c0a22dfc>] (spi_nor_probe+0xd0/0x190)
[    2.191513] [<c0a22dfc>] (spi_nor_probe) from [<c0a370a0>] (spi_drv_probe+0x80/0xa4)
[    2.199268] [<c0a370a0>] (spi_drv_probe) from [<c0957f8c>] (really_probe+0x234/0x34c)
[    2.207111] [<c0957f8c>] (really_probe) from [<c095821c>] (driver_probe_device+0x60/0x174)
[    2.215391] [<c095821c>] (driver_probe_device) from [<c0956378>] (bus_for_each_drv+0x58/0xb8)
[    2.223932] [<c0956378>] (bus_for_each_drv) from [<c0957ce4>] (__device_attach+0xd0/0x13c)
[    2.232212] [<c0957ce4>] (__device_attach) from [<c0957060>] (bus_probe_device+0x84/0x8c)
[    2.240404] [<c0957060>] (bus_probe_device) from [<c0953fb4>] (device_add+0x3bc/0x608)
[    2.248334] [<c0953fb4>] (device_add) from [<c0a377b4>] (spi_add_device+0x9c/0x14c)
[    2.256003] [<c0a377b4>] (spi_add_device) from [<c0a37b98>] (of_register_spi_device+0x234/0x370)
[    2.264807] [<c0a37b98>] (of_register_spi_device) from [<c0a384ec>] (spi_register_controller+0x578/0x734)
[    2.274394] [<c0a384ec>] (spi_register_controller) from [<c0a386dc>] (devm_spi_register_controller+0x34/0x6c)
[    2.284331] [<c0a386dc>] (devm_spi_register_controller) from [<c0a4d0b8>] (stm32_qspi_probe+0x338/0x3bc)
[    2.293831] [<c0a4d0b8>] (stm32_qspi_probe) from [<c0959ee0>] (platform_drv_probe+0x48/0x98)
[    2.302285] [<c0959ee0>] (platform_drv_probe) from [<c0957f8c>] (really_probe+0x234/0x34c)
[    2.310566] [<c0957f8c>] (really_probe) from [<c095821c>] (driver_probe_device+0x60/0x174)
[    2.318847] [<c095821c>] (driver_probe_device) from [<c09584d8>] (device_driver_attach+0x58/0x60)
[    2.327735] [<c09584d8>] (device_driver_attach) from [<c0958560>] (__driver_attach+0x80/0xbc)
[    2.336276] [<c0958560>] (__driver_attach) from [<c09562cc>] (bus_for_each_dev+0x74/0xb4)
[    2.344469] [<c09562cc>] (bus_for_each_dev) from [<c09572c4>] (bus_add_driver+0x164/0x1e8)
[    2.352749] [<c09572c4>] (bus_add_driver) from [<c0958fd8>] (driver_register+0x74/0x108)
[    2.360854] [<c0958fd8>] (driver_register) from [<c0302ec8>] (do_one_initcall+0x54/0x22c)
[    2.369047] [<c0302ec8>] (do_one_initcall) from [<c1501024>] (kernel_init_freeable+0x150/0x1ec)
[    2.377762] [<c1501024>] (kernel_init_freeable) from [<c0ea5e74>] (kernel_init+0x8/0x114)
[    2.385951] [<c0ea5e74>] (kernel_init) from [<c03010e8>] (ret_from_fork+0x14/0x2c)
[    2.393525] Exception stack(0xe68c1fb0 to 0xe68c1ff8)
[    2.398583] 1fa0:                                     00000000 00000000 00000000 00000000
[    2.406777] 1fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[    2.414967] 1fe0: 00000000 00000000 00000000 00000000 00000013 00000000
[    2.421879] mtd mtd4: Failed to register NVMEM device

Before nvmen device registration was added, it was possible to have same partition name on different devices.
Instead of using the partition name, this patch proposes to use the MTD device name (mtdX).

Regards,
Christophe Kerello.

 drivers/mtd/mtdcore.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 5fac435..559b693 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -551,7 +551,7 @@ static int mtd_nvmem_add(struct mtd_info *mtd)
 
 	config.id = -1;
 	config.dev = &mtd->dev;
-	config.name = mtd->name;
+	config.name = dev_name(&mtd->dev);
 	config.owner = THIS_MODULE;
 	config.reg_read = mtd_nvmem_reg_read;
 	config.size = mtd->size;
-- 
1.9.1