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authorDan Williams <dan.j.williams@intel.com>2023-06-16 18:24:39 -0700
committerDan Williams <dan.j.williams@intel.com>2023-06-25 13:45:40 -0700
commitadfe19738b71a893da62cb2e30bd6bdb4299ea67 (patch)
tree8b835f06608d62794b3fce9ccca0df007e99f002 /drivers/cxl
parent2ab47045ac96a605e3037d479a7d5854570ee5bf (diff)
downloadlwn-adfe19738b71a893da62cb2e30bd6bdb4299ea67.tar.gz
lwn-adfe19738b71a893da62cb2e30bd6bdb4299ea67.zip
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 <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@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/cxl')
-rw-r--r--drivers/cxl/core/region.c26
1 files changed, 15 insertions, 11 deletions
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index fa29bd2ec322..bfdd424d6897 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);