From: Dan Williams dan.j.williams@intel.com
[ Upstream commit adfe19738b71a893da62cb2e30bd6bdb4299ea67 ]
Jonathan reports that failed attempts to reset a region (teardown its HDM decoder configuration) mistakenly advance the state of the region to "not committed". Revert to the previous state of the region on reset failure so that the reset can be re-attempted.
Reported-by: Jonathan Cameron Jonathan.Cameron@Huawei.com Closes: http://lore.kernel.org/r/20230316171441.0000205b@Huawei.com Fixes: 176baefb2eb5 ("cxl/hdm: Commit decoder state to hardware") Reviewed-by: Jonathan Cameron Jonathan.Cameron@huawei.com Reviewed-by: Dave Jiang dave.jiang@intel.com Link: https://lore.kernel.org/r/168696507968.3590522.14484000711718573626.stgit@dw... Signed-off-by: Dan Williams dan.j.williams@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/cxl/core/region.c | 26 +++++++++++++++----------- 1 file changed, 15 insertions(+), 11 deletions(-)
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index c1422167ab02b..1997bc1bf64aa 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -296,9 +296,11 @@ static ssize_t commit_store(struct device *dev, struct device_attribute *attr, if (rc) return rc;
- if (commit) + if (commit) { rc = cxl_region_decode_commit(cxlr); - else { + if (rc == 0) + p->state = CXL_CONFIG_COMMIT; + } else { p->state = CXL_CONFIG_RESET_PENDING; up_write(&cxl_region_rwsem); device_release_driver(&cxlr->dev); @@ -308,18 +310,20 @@ static ssize_t commit_store(struct device *dev, struct device_attribute *attr, * The lock was dropped, so need to revalidate that the reset is * still pending. */ - if (p->state == CXL_CONFIG_RESET_PENDING) + if (p->state == CXL_CONFIG_RESET_PENDING) { rc = cxl_region_decode_reset(cxlr, p->interleave_ways); + /* + * Revert to committed since there may still be active + * decoders associated with this region, or move forward + * to active to mark the reset successful + */ + if (rc) + p->state = CXL_CONFIG_COMMIT; + else + p->state = CXL_CONFIG_ACTIVE; + } }
- if (rc) - goto out; - - if (commit) - p->state = CXL_CONFIG_COMMIT; - else if (p->state == CXL_CONFIG_RESET_PENDING) - p->state = CXL_CONFIG_ACTIVE; - out: up_write(&cxl_region_rwsem);