[PATCH 0/2] drm/radeon: have the callers of set_memory_*() check the return value

From: Tianlin Li
Date: Tue Jan 07 2020 - 14:26:03 EST

Right now several architectures allow their set_memory_*() family of
functions to fail, but callers may not be checking the return values.
If set_memory_*() returns with an error, call-site assumptions may be
infact wrong to assume that it would either succeed or not succeed at
all. Ideally, the failure of set_memory_*() should be passed up the
call stack, and callers should examine the failure and deal with it.

Need to fix the callers and add the __must_check attribute. They also
may not provide any level of atomicity, in the sense that the memory
protections may be left incomplete on failure. This issue likely has a
few steps on effects architectures:
1)Have all callers of set_memory_*() helpers check the return value.
2)Add __must_check to all set_memory_*() helpers so that new uses do
not ignore the return value.
3)Add atomicity to the calls so that the memory protections aren't left
in a partial state.

This series is part of step 1. Make drm/radeon check the return value of

Tianlin Li (2):
drm/radeon: have the callers of set_memory_*() check the return value
drm/radeon: change call sites to handle return value properly.

drivers/gpu/drm/radeon/r100.c | 3 ++-
drivers/gpu/drm/radeon/radeon.h | 2 +-
drivers/gpu/drm/radeon/radeon_gart.c | 22 ++++++++++++++++++----
drivers/gpu/drm/radeon/rs400.c | 3 ++-
4 files changed, 23 insertions(+), 7 deletions(-)