Re: [PATCH v2 1/2] pmdomain: imx8mp-blk-ctrl: keep gpc power domain on if blk-ctrl pd is on during system pm

[Frieder Schrempf]

On 23.07.26 14:49, Frieder Schrempf wrote:
> Hi,
> 
> On 04.02.26 12:11, Xu Yang wrote:
>> Current design will power off all dependent GPC power domains in
>> imx8mp_blk_ctrl_suspend(), even though the user device has enabled
>> wakeup capability. The result is that wakeup function never works
>> for such device.
>>
>> An example will be USB wakeup on i.MX8MP. PHY device '382f0040.usb-phy'
>> is attached to power domain 'hsioblk-usb-phy2' which is spawned by hsio
>> block control. A virtual power domain device 'genpd:3:32f10000.blk-ctrl'
>> is created to build connection with 'hsioblk-usb-phy2' and it depends on
>> GPC power domain 'usb-otg2'. If device '382f0040.usb-phy' enable wakeup,
>> only power domain 'hsioblk-usb-phy2' keeps on during system suspend,
>> power domain 'usb-otg2' is off all the time. So the wakeup event can't
>> happen.
>>
>> In order to further establish a connection between the power domains
>> related to GPC and block control during system pm, register a notifier
>> to power_dev, so that GPC power domain will know that block control power
>> domain is on and will not power off itself.
>>
>> Suggested-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
>> Fixes: 556f5cf9568a ("soc: imx: add i.MX8MP HSIO blk-ctrl")
>> Cc: stable@xxxxxxxxxx
>> Signed-off-by: Xu Yang <xu.yang_2@xxxxxxx>
> This patch got backported to v6.1.y and for me it breaks the boot on
> i.MX8MP with the log below (tested with 6.1.175).
> 
> Reverting the two patches of this series fixes the issue. What is the
> correct way to fix this for the 6.1 stable branch? Should the patches be
> reverted?
> 

Ah, this is probably related to the fact, that I also carry backported
HDMI support in our 6.1 tree. This likely triggers the exception and I'm
probably the only one seeing this as this is specific to our tree.

> Thanks
> Frieder
> 
> [    1.164011] imx8mp-blk-ctrl 32fc0000.blk-ctrl: error -ENODEV: failed
> to add power notifier
> [    1.171108] Unable to handle kernel NULL pointer dereference at
> virtual address 0000000000000210
> [    1.179932] Mem abort info:
> [    1.182731]   ESR = 0x0000000096000004
> [    1.186492]   EC = 0x25: DABT (current EL), IL = 32 bits
> [    1.191833]   SET = 0, FnV = 0
> [    1.194891]   EA = 0, S1PTW = 0
> [    1.198041]   FSC = 0x04: level 0 translation fault
> [    1.202960] Data abort info:
> [    1.205836]   ISV = 0, ISS = 0x00000004
> [    1.209676]   CM = 0, WnR = 0
> [    1.212662] [0000000000000210] user address but active_mm is swapper
> [    1.219044] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
> [    1.225340] Modules linked in:
> [    1.228403] CPU: 2 PID: 1 Comm: swapper/0 Not tainted
> 6.1.175-ktn-ked-0.0.0 #1
> [    1.235663] Hardware name: Kontron BL i.MX8MP OSM-S (DT)
> [    1.241001] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS
> BTYPE=--)
> [    1.247999] pc : dev_pm_domain_detach+0x0/0x40
> [    1.252461] lr : imx8mp_blk_ctrl_probe+0x494/0x580
> [    1.257276] sp : ffff80000997ba00
> [    1.260601] x29: ffff80000997bb70 x28: ffff0000c0aaa9a0 x27:
> 00000000ffffffed
> [    1.267774] x26: ffff800008e37c78 x25: ffff800008e37ab8 x24:
> ffff800008e37af0
> [    1.274949] x23: 0000000000000007 x22: ffff0000c0945010 x21:
> 0000000000000038
> [    1.282124] x20: 0000000000000188 x19: ffff0000c0fa6580 x18:
> ffffffffffffffff
> [    1.289299] x17: 20646461206f7420 x16: 64656c696166203a x15:
> 5645444f4e452d20
> [    1.296474] x14: 726f727265203a6c x13: 7265696669746f6e x12:
> ffff80000962c280
> [    1.303649] x11: 00000000000000dd x10: ffff80000962c280 x9 :
> 00000000ffffdfff
> [    1.310824] x8 : ffff8000096dc280 x7 : 000000000002ffe8 x6 :
> 0000000000000000
> [    1.318001] x5 : 80000000ffffe000 x4 : 0000000000000000 x3 :
> 0000000000000000
> [    1.325174] x2 : 0000000000000000 x1 : 0000000000000001 x0 :
> 0000000000000000
> [    1.332351] Call trace:
> [    1.334801]  dev_pm_domain_detach+0x0/0x40
> [    1.338913]  platform_probe+0x68/0xe0
> [    1.342586]  really_probe+0xc0/0x3e0
> [    1.346174]  __driver_probe_device+0x84/0x190
> [    1.350549]  driver_probe_device+0x3c/0x110
> [    1.354751]  __driver_attach+0xf4/0x200
> [    1.358599]  bus_for_each_dev+0x74/0xe0
> [    1.362451]  driver_attach+0x24/0x30
> [    1.366038]  bus_add_driver+0x17c/0x240
> [    1.369886]  driver_register+0x78/0x130
> [    1.373736]  __platform_driver_register+0x24/0x30
> [    1.378463]  imx8mp_blk_ctrl_driver_init+0x1c/0x28
> [    1.383274]  do_one_initcall+0x48/0x2b0
> [    1.387126]  kernel_init_freeable+0x22c/0x29c
> [    1.391499]  kernel_init+0x24/0x134
> [    1.395001]  ret_from_fork+0x10/0x20
> [    1.398592] Code: d65f03c0 d65f03c0 00000000 00000000 (f9410802)
> [    1.404715] ---[ end trace 0000000000000000 ]---
> 
>