[PATCH v2 0/3] drm/amdgpu: Remove in_interrupt() usage.

[Sebastian Andrzej Siewior]

On 2021-02-09 18:43:54 [+0100], Christian König wrote:
> Hi Sebastian,
Hi Christian,

> to be honest I'm thinking about that for quite some time now and I don't
> think that this is possible without a severe rewrite of the driver.
> 
> The problem is simply that we have a lot of functions which deal with
> hardware handling independent of the context. But how registers are accessed
> needs to be different depending if your are in the interrupt handler or not.
> 
> You would need to push the information if we are coming in from the
> interrupt handler through a > 10 function calls.
> 
> I don't think that this is feasible nor good design.

Yeah, that is what I saw and didn't even try.

The possible backtrace (at the bottom of this email) is this a correct
assumption?

Another quick question: You acked my three-patch series. I don't see it
in the next tree as of today. Is there anything for me to do?

> Regards,
> Christian.
> 
> Am 09.02.21 um 17:53 schrieb Sebastian Andrzej Siewior:
> > On 2021-02-09 13:50:31 [+0100], Christian König wrote:
> > > Reviewed-by: Christian König <christian.koenig at amd.com> for the series.
> > Thank you.
> > Any chance you could give me a hand with the remaining three users
> > within the amdgpu driver? I don't know if the in_interrupt() check can
> > be limited to certain callers.
> > What I noticed while tracing v5.10 is this:
> > 
> > |             Xorg-2257    [007] d... 57261.620043: amdgpu_device_wreg: 0x699f, 0x00001bcf, 0x00000100
> > |  => trace_event_raw_event_amdgpu_device_wreg
> > |  => amdgpu_device_wreg.part.0
> > |  => dce110_arm_vert_intr
> > |  => dce110_vblank_set
> > |  => dm_enable_vblank
> > |  => drm_vblank_enable
> > |  => drm_vblank_get
> > |  => drm_wait_vblank_ioctl
> > |  => drm_ioctl_kernel
> > |  => drm_ioctl
> > |  => amdgpu_drm_ioctl
> > |  => __x64_sys_ioctl
> > |  => do_syscall_64
> > |  => entry_SYSCALL_64_after_hwframe
> > 
> > I think that amdgpu_device_wreg() -> amdgpu_kiq_wreg() could be invoked.
> > It doesn't here because amdgpu_sriov_runtime() is false.
> > The trace says `d' which means interrupts are disabled but
> > in_interrupt() will return false in this case (no IRQ/softirq).
> > 
> > Sebastian

Sebastian