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| author | Huang Ying <ying.huang@intel.com> | 2023-12-08 11:06:36 +0800 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2024-01-04 13:59:50 -0800 |
| commit | d6488fee66472b468ed88d265b14aa3f04dc3bdf (patch) | |
| tree | b8b74ad3e07dacc83814d010c17b8eaa36f0c1b4 /drivers | |
| parent | ceb6a6f023fd3e8b07761ed900352ef574010bcb (diff) | |
| download | linux-stable-d6488fee66472b468ed88d265b14aa3f04dc3bdf.tar.gz linux-stable-d6488fee66472b468ed88d265b14aa3f04dc3bdf.tar.bz2 linux-stable-d6488fee66472b468ed88d265b14aa3f04dc3bdf.zip | |
cxl/port: Fix decoder initialization when nr_targets > interleave_ways
The decoder_populate_targets() helper walks all of the targets in a port
and makes sure they can be looked up in @target_map. Where @target_map
is a lookup table from target position to target id (corresponding to a
cxl_dport instance). However @target_map is only responsible for
conveying the active dport instances as indicated by interleave_ways.
When nr_targets > interleave_ways it results in
decoder_populate_targets() walking off the end of the valid entries in
@target_map. Given target_map is initialized to 0 it results in the
dport lookup failing if position 0 is not mapped to a dport with an id
of 0:
cxl_port port3: Failed to populate active decoder targets
cxl_port port3: Failed to add decoder
cxl_port port3: Failed to add decoder3.0
cxl_bus_probe: cxl_port port3: probe: -6
This bug also highlights that when the decoder's ->targets[] array is
written in cxl_port_setup_targets() it is missing a hold of the
targets_lock to synchronize against sysfs readers of the target list. A
fix for that is saved for a later patch.
Fixes: a5c258021689 ("cxl/bus: Populate the target list at decoder create")
Cc: <stable@vger.kernel.org>
Signed-off-by: Huang, Ying <ying.huang@intel.com>
[djbw: rewrite the changelog, find the Fixes: tag]
Co-developed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/cxl/core/port.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c index b7c93bb18f6e..57495cdc181f 100644 --- a/drivers/cxl/core/port.c +++ b/drivers/cxl/core/port.c @@ -1644,7 +1644,7 @@ static int decoder_populate_targets(struct cxl_switch_decoder *cxlsd, return -EINVAL; write_seqlock(&cxlsd->target_lock); - for (i = 0; i < cxlsd->nr_targets; i++) { + for (i = 0; i < cxlsd->cxld.interleave_ways; i++) { struct cxl_dport *dport = find_dport(port, target_map[i]); if (!dport) { |