From adfe19738b71a893da62cb2e30bd6bdb4299ea67 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Fri, 16 Jun 2023 18:24:39 -0700 Subject: [PATCH] cxl/region: Fix state transitions after reset failure 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 Closes: http://lore.kernel.org/r/20230316171441.0000205b@Huawei.com Fixes: 176baefb2eb5 ("cxl/hdm: Commit decoder state to hardware") Reviewed-by: Jonathan Cameron Reviewed-by: Dave Jiang Link: https://lore.kernel.org/r/168696507968.3590522.14484000711718573626.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams --- 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 fa29bd2..bfdd424 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); -- 2.7.4