Hi Marek,
On Thu, Mar 25, 2021 at 2:32 PM Marek Szyprowski
[off-list ref] wrote:
On 10.02.2021 12:44, Tudor Ambarus wrote:
quoted
This is a follow-up for:
commit 3c9ea42802a1 ("clk: Mark fwnodes when their clock provider is added/removed")
The above commit updated the deprecated of_clk_add_provider(),
but missed to update the preferred of_clk_add_hw_provider().
Update it now.
Signed-off-by: Tudor Ambarus <redacted>
This patch, which landed in linux-next as commit 6579c8d97ad7 ("clk:
Mark fwnodes when their clock provider is added") causes the following
NULL pointer dereference on Raspberry Pi 3b+ boards:
--->8---
raspberrypi-firmware soc:firmware: Attached to firmware from
2020-01-06T13:05:25
Unable to handle kernel NULL pointer dereference at virtual address
0000000000000050
Mem abort info:
ESR = 0x96000004
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
Data abort info:
ISV = 0, ISS = 0x00000004
CM = 0, WnR = 0
[0000000000000050] user address but active_mm is swapper
Internal error: Oops: 96000004 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 10 Comm: kworker/0:1 Not tainted 5.12.0-rc4+ #2764
Hardware name: Raspberry Pi 3 Model B (DT)
Workqueue: events deferred_probe_work_func
pstate: 00000005 (nzcv daif -PAN -UAO -TCO BTYPE=--)
pc : of_clk_add_hw_provider+0xac/0xe8
lr : of_clk_add_hw_provider+0x94/0xe8
sp : ffff8000130936b0
x29: ffff8000130936b0 x28: ffff800012494e04
x27: ffff00003b18cb05 x26: ffff00003aa5c010
x25: 0000000000000000 x24: 0000000000000000
x23: ffff00003aa1e380 x22: ffff8000106830d0
x21: ffff80001233f180 x20: 0000000000000018
x19: 0000000000000000 x18: ffff8000124d38b0
x17: 0000000000000013 x16: 0000000000000014
x15: ffff8000125758b0 x14: 00000000000184e0
x13: 000000000000292e x12: ffff80001258dd98
x11: 0000000000000001 x10: 0101010101010101
x9 : ffff80001233f288 x8 : 7f7f7f7f7f7f7f7f
x7 : fefefefeff6c626f x6 : 5d636d8080808080
x5 : 00000000006d635d x4 : 0000000000000000
x3 : 0000000000000000 x2 : 540eb5edae191600
x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
of_clk_add_hw_provider+0xac/0xe8
devm_of_clk_add_hw_provider+0x5c/0xb8
raspberrypi_clk_probe+0x110/0x210
platform_probe+0x90/0xd8
really_probe+0x108/0x3c0
driver_probe_device+0x60/0xc0
__device_attach_driver+0x9c/0xd0
bus_for_each_drv+0x70/0xc8
__device_attach+0xec/0x150
device_initial_probe+0x10/0x18
bus_probe_device+0x94/0xa0
device_add+0x47c/0x780
platform_device_add+0x110/0x248
platform_device_register_full+0x120/0x150
rpi_firmware_probe+0x158/0x1f8
This patch mainly revealed that clk/bcm/clk-raspberrypi.c driver calls
devm_of_clk_add_hw_provider(), with a device pointer, which has a NULL
dev->of_node. I'm not sure if adding a check for a NULL np in
of_clk_add_hw_provider() is a right fix, though.
raspberrypi_clk_probe():
/*
* We can be probed either through the an old-fashioned
* platform device registration or through a DT node that is a
* child of the firmware node. Handle both cases.
*/
So the real issue is rpi_register_clk_driver() creating a platform
device for the firmware clocks if they're missing in DT.
Then, the clock driver calls devm_of_clk_add_hw_provider(),
regardless of a DT node being present or not.
I'm wondering how power consumers are supposed to refer
to these firmware clocks, without a DT node?
quoted
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -4594,6 +4594,8 @@ int of_clk_add_hw_provider(struct device_node *np,
if (ret < 0)
of_clk_del_provider(np);
+ fwnode_dev_initialized(&np->fwnode, true);
+
return ret;
}
EXPORT_SYMBOL_GPL(of_clk_add_hw_provider);
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds