The fsl-mc bus associated to the root DPRC in a DPAA2 system exports a
device file for userspace access to the MC firmware. In case the DPRC's
local MC portal (DPMCP) is currently in use, a new DPMCP device is
allocated through the fsl_mc_portal_allocate() function.
In this case, the call to fsl_mc_portal_allocate() will fail with -EINVAL
when trying to add a device link between the root DPRC (consumer) and
the newly allocated DPMCP device (supplier). This is because the DPMCP
is a dependent of the DPRC device (the bus).
Fix this by not adding a device link in case the DPMCP is allocated for
the root DPRC's usage.
Fixes: afb77422819f ("bus: fsl-mc: automatically add a device_link on
fsl_mc_[portal,object]_allocate")
Signed-off-by: Ioana Ciornei <ioana.cior...@nxp.com>
Cc: sta...@vger.kernel.org
---
drivers/bus/fsl-mc/mc-io.c | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)
diff --git a/drivers/bus/fsl-mc/mc-io.c b/drivers/bus/fsl-mc/mc-io.c
index a0ad7866cbfc..cd8754763f40 100644
--- a/drivers/bus/fsl-mc/mc-io.c
+++ b/drivers/bus/fsl-mc/mc-io.c
@@ -214,12 +214,19 @@ int __must_check fsl_mc_portal_allocate(struct
fsl_mc_device *mc_dev,
if (error < 0)
goto error_cleanup_resource;
- dpmcp_dev->consumer_link = device_link_add(&mc_dev->dev,
- &dpmcp_dev->dev,
- DL_FLAG_AUTOREMOVE_CONSUMER);
- if (!dpmcp_dev->consumer_link) {
- error = -EINVAL;
- goto error_cleanup_mc_io;
+ /* If the DPRC device itself tries to allocate a portal (usually for
+ * UAPI interaction), don't add a device link between them since the
+ * DPMCP device is an actual child device of the DPRC and a reverse
+ * dependency is not allowed.
+ */
+ if (mc_dev != mc_bus_dev) {
+ dpmcp_dev->consumer_link = device_link_add(&mc_dev->dev,
+ &dpmcp_dev->dev,
+
DL_FLAG_AUTOREMOVE_CONSUMER);
+ if (!dpmcp_dev->consumer_link) {
+ error = -EINVAL;
+ goto error_cleanup_mc_io;
+ }
}
*new_mc_io = mc_io;
--
2.34.1
