| From 9a080955d841a87deb907359ea5c374775a31b5c Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Fri, 16 Jun 2023 18:24:39 -0700 |
| Subject: cxl/region: Fix state transitions after reset failure |
| |
| 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@dwillia2-xfh.jf.intel.com |
| 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); |
| |
| -- |
| 2.39.2 |
| |
