linux_dsm_epyc7002/drivers/gpu
Daniel Vetter 4fb066ab9e drm/i915: close PM interrupt masking races in the irq handler
Quoting Chris Wilson's more concise description:

"Ah I think I see the problem. As you point out we only mask the current
interrupt received, so that if we have a task pending (and so IMR != 0) we
actually unmask the pending interrupt and so could receive it again before the
tasklet is finally kicked off by the grumpy scheduler."

We need the hw to issue PM interrupts A, B, A while the scheduler is hating us
and refuses to run the rps work item. On receiving PM interrupt A we hit the
WARN because

dev_priv->pm_iir == PM_A | PM_B

Also add a posting read as suggested by Chris to ensure proper ordering of the
writes to PMIMR and PMIIR. Just in case somebody weakens write ordering.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Keith Packard <keithp@keithp.com>
2011-10-20 14:11:16 -07:00
..
drm drm/i915: close PM interrupt masking races in the irq handler 2011-10-20 14:11:16 -07:00
stub i915: select VIDEO_OUTPUT_CONTROL for ACPI_VIDEO 2011-04-13 09:10:25 +10:00
vga drivers: use kzalloc/kcalloc instead of 'kmalloc+memset', where possible 2011-07-25 20:57:13 -07:00
Makefile gpu: Add Intel GMA500(Poulsbo) Stub Driver 2010-10-26 11:00:13 +10:00