| Message ID | 20201021232554.1434687-1-oohall@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 99f6e9795a68fe23f96a2b5b0be07a3dd9457f99 |
| Headers | show |
| Series | powerpc/eeh: Fix eeh_dev_check_failure() for PE#0 | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/apply_patch | success | Successfully applied on branch powerpc/merge (598b738031de83cadbcf745ad0ad2bd69a0ee012) |
| snowpatch_ozlabs/build-ppc64le | warning | Upstream build failed, couldn't test patch |
| snowpatch_ozlabs/build-ppc64be | warning | Upstream build failed, couldn't test patch |
| snowpatch_ozlabs/build-ppc64e | warning | Upstream build failed, couldn't test patch |
| snowpatch_ozlabs/build-pmac32 | warning | Upstream build failed, couldn't test patch |
| snowpatch_ozlabs/checkpatch | success | |
| snowpatch_ozlabs/needsstable | success | Patch fixes a commit that hasn't been released yet |
On Thu, 22 Oct 2020 10:25:54 +1100, Oliver O'Halloran wrote: > In commit 269e583357df ("powerpc/eeh: Delete eeh_pe->config_addr") the > following simplification was made: > > - if (!pe->addr && !pe->config_addr) { > + if (!pe->addr) { > eeh_stats.no_cfg_addr++; > return 0; > } > > [...] Applied to powerpc/fixes. [1/1] powerpc/eeh: Fix eeh_dev_check_failure() for PE#0 https://git.kernel.org/powerpc/c/99f6e9795a68fe23f96a2b5b0be07a3dd9457f99 cheers
diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c index 4da880759a8b..7dd03d47693f 100644 --- a/arch/powerpc/kernel/eeh.c +++ b/arch/powerpc/kernel/eeh.c @@ -470,11 +470,6 @@ int eeh_dev_check_failure(struct eeh_dev *edev) return 0; } - if (!pe->addr) { - eeh_stats.no_cfg_addr++; - return 0; - } - /* * On PowerNV platform, we might already have fenced PHB * there and we need take care of that firstly.
In commit 269e583357df ("powerpc/eeh: Delete eeh_pe->config_addr") the following simplification was made: - if (!pe->addr && !pe->config_addr) { + if (!pe->addr) { eeh_stats.no_cfg_addr++; return 0; } This introduced a bug which causes EEH checking to be skipped for devices in PE#0. Before the change above the check would always pass since atleast one of the two PE addresses would be non-zero in all circumstances. On PowerNV pe->config_addr was the be the BDFN of the first device added to the PE. The zero BDFN is reserved for the PHB's root port, but this is fine since for obscure platform reasons the root port is never assigned to PE#0. Similarly, on pseries pe->addr has always been non-zero for the reasons outlined in commit 42de19d5ef71 ("powerpc/pseries/eeh: Allow zero to be a valid PE configuration address"). We can fix the problem by deleting the block entirely The original purpose of this test was to avoid performing EEH checks on devices there were not on an EEH capable bus. In modern Linux the edev->pe pointer will be NULL for devices that are not on an EEH capable bus. The code block immediately above this one already checks for the edev->pe == NULL case so this test (new and old) is entirely redundant. Ideally we'd delete eeh_stats.no_cfg_addr too since nothing increments it any more. Unfortunately, that information is exposed via /proc/powerpc/eeh which means it's technically ABI. We could make it hard-coded, but that's a change for another patch. Fixes: 269e583357df ("powerpc/eeh: Delete eeh_pe->config_addr") Signed-off-by: Oliver O'Halloran <oohall@gmail.com> --- arch/powerpc/kernel/eeh.c | 5 ----- 1 file changed, 5 deletions(-)