RE: [Linuxarm] [PATCH v2] input - mk712: remove the driver as it is obsolete and causes kernel crash

["Song Bao Hua (Barry Song)" <song.bao.hua@hisilicon.com>]

> -----Original Message-----
> From: John Garry
> Sent: Tuesday, January 12, 2021 11:55 PM
> To: Song Bao Hua (Barry Song) <song.bao.hua@hisilicon.com>;
> dmitry.torokhov@gmail.com; linux-input@vger.kernel.org
> Cc: linuxarm@openeuler.org; Daniel Quinlan <quinlan@pathname.com>; Vojtech
> Pavlik <vojtech@suse.cz>
> Subject: Re: [Linuxarm] [PATCH v2] input - mk712: remove the driver as it is
> obsolete and causes kernel crash
> 
> On 12/01/2021 05:51, Barry Song wrote:
> > While debugging other issues, I enabled mk712 then I got the below crash
> > during arm64 linux boot:
> > [    1.150412] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO BTYPE=--)
> > [    1.150541] pc : logic_outb+0x3c/0xa8
> > [    1.150657] lr : mk712_init+0x74/0x1ec
> > [    1.150745] sp : ffff800011efbd40
> > [    1.150950] x29: ffff800011efbd40 x28: 0000000000000000
> > [    1.151098] x27: ffff800011681078 x26: ffff8000115d04b8
> > [    1.151192] x25: ffff8000116ff6b4 x24: ffff8000115bac10
> > [    1.151287] x23: ffff800011dfa000 x22: ffff800011b8dbe0
> > [    1.151421] x21: ffff800011eac000 x20: 0000000000000000
> > [    1.151527] x19: fffffbfffe800266 x18: 0000000000000000
> > [    1.151674] x17: ffff800010a7bc38 x16: ffff800010a7b0e0
> > [    1.151944] x15: 0000a0d665e7ee58 x14: 000000000000011a
> > [    1.152060] x13: 0000000000000001 x12: 0000000000000000
> > [    1.152149] x11: 0000000000000000 x10: 0000000000000a60
> > [    1.152291] x9 : 0000000000000000 x8 : ffff0000c0a2a480
> > [    1.152429] x7 : 0000000000000000 x6 : ffff0000c0b0c9b8
> > [    1.152522] x5 : 0000000000001000 x4 : ffff0000c03613b0
> > [    1.152614] x3 : 0000000000000267 x2 : 0000000000000260
> > [    1.152731] x1 : fffffbfffe800000 x0 : 0000000000ffbffe
> > [    1.153135] Call trace:
> > [    1.153342]  logic_outb+0x3c/0xa8
> > [    1.153434]  mk712_init+0x74/0x1ec
> > [    1.153571]  do_one_initcall+0x54/0x1b8
> > [    1.153705]  kernel_init_freeable+0x1d0/0x238
> > [    1.153860]  kernel_init+0x14/0x118
> > [    1.153960]  ret_from_fork+0x10/0x30
> > [    1.154304] Code: d2bfd001 f2df7fe1 f2ffffe1 8b010273 (39000274)
> > [    1.155013] ---[ end trace f9b157c311d20edd ]---
> > [    1.155854] Kernel panic - not syncing: Attempted to kill init!
> exitcode=0x0000000b
> > [    1.156236] SMP: stopping secondary CPUs
> >
> > The driver is very old and resources are totally hardcoded, no bus model.
> > And it seems there is no way to stop users from enabling it in Kconfig.
> > Plus, it is likely that there is no "Gateway AOL Connected Touchpad
> > computers" running 5.x kernel any more. So remove this driver.
> >
> > Cc: Daniel Quinlan<quinlan@pathname.com>
> > Cc: Vojtech Pavlik<vojtech@suse.cz>
> > Signed-off-by: Barry Song<song.bao.hua@hisilicon.com>
> 
> JFYI, this is a common problem for many IO port drivers on architectures
> which don't natively support IO ports, like arm64 and powerpc. Some
> drivers guard against it simply by depending on !ARCH_XXX, like:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/dr
> ivers/hwmon/Kconfig?h=v5.11-rc3#n551
> 
> But not a great solution.

Yep. It looks buggy as powerpc and arm64 could have the device literally
though practically people might not use them.

> 
> I tried to guard against it in this series, but never got it over the line:
> https://lore.kernel.org/linux-pci/1560262374-67875-1-git-send-email-john.g
> arry@huawei.com/

Cool. I didn't realize you have tried to figure out a patchset
to fix it in common code. It seems it is worth revisiting the
patchset?

> 
> Thanks,
> John

Thanks
Barry