cxl/region: Fix region commit uninitialized variable warning

0day robot reports:

drivers/cxl/core/region.c:196 cxl_region_decode_commit() error: uninitialized symbol 'rc'.

The re-checking of loop termination conditions to determine "success"
makes it hard to see that @rc is initialized in all cases. Remove those
to make it explicit that @rc reflects a commit error and that the rest
of logic is concerned with unwinding committed decoders.

This change potentially results in cxl_region_decode_reset() being
called with @count == 0 where it was not called before, but
cxl_region_decode_reset() treats that as a nop.

Fixes: 176baefb2eb5 ("cxl/hdm: Commit decoder state to hardware")
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: http://lore.kernel.org/r/165951148105.967013.14191992449932268431.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index 25502c9..addab74 100644 (file)
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -159,7 +159,7 @@ static int cxl_region_decode_reset(struct cxl_region *cxlr, int count)
 static int cxl_region_decode_commit(struct cxl_region *cxlr)
 {
        struct cxl_region_params *p = &cxlr->params;
-       int i, rc;
+       int i, rc = 0;
 
        for (i = 0; i < p->nr_targets; i++) {
                struct cxl_endpoint_decoder *cxled = p->targets[i];
@@ -179,27 +179,23 @@ static int cxl_region_decode_commit(struct cxl_region *cxlr)
                                break;
                }
 
-               /* success, all decoders up to the root are programmed */
-               if (is_cxl_root(iter))
-                       continue;
+               if (rc) {
+                       /* programming @iter failed, teardown */
+                       for (ep = cxl_ep_load(iter, cxlmd); ep && iter;
+                            iter = ep->next, ep = cxl_ep_load(iter, cxlmd)) {
+                               cxl_rr = cxl_rr_load(iter, cxlr);
+                               cxld = cxl_rr->decoder;
+                               cxld->reset(cxld);
+                       }
 
-               /* programming @iter failed, teardown */
-               for (ep = cxl_ep_load(iter, cxlmd); ep && iter;
-                    iter = ep->next, ep = cxl_ep_load(iter, cxlmd)) {
-                       cxl_rr = cxl_rr_load(iter, cxlr);
-                       cxld = cxl_rr->decoder;
-                       cxld->reset(cxld);
+                       cxled->cxld.reset(&cxled->cxld);
+                       goto err;
                }
-
-               cxled->cxld.reset(&cxled->cxld);
-               if (i == 0)
-                       return rc;
-               break;
        }
 
-       if (i >= p->nr_targets)
-               return 0;
+       return 0;
 
+err:
        /* undo the targets that were successfully committed */
        cxl_region_decode_reset(cxlr, i);
        return rc;