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bus: fsl-mc: do not add a device-link for the UAPI used DPMCP device

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commit dd7d8e012b23de158ca0188239c7a1f2a83b4484 upstream.

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: afb7742281 ("bus: fsl-mc: automatically add a device_link on fsl_mc_[portal,object]_allocate")
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250408105814.2837951-3-ioana.ciornei@nxp.com
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Ioana Ciornei
2025-04-08 13:58:10 +03:00
committed by Greg Kroah-Hartman
parent 8edfed4439
commit 1e474b5fab
1 changed files with 13 additions and 6 deletions
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19
drivers/bus/fsl-mc/mc-io.c
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@@ -214,12 +214,19 @@ int __must_check fsl_mc_portal_allocate(struct fsl_mc_device *mc_dev,
if (error < 0) if (error < 0)
goto error_cleanup_resource; goto error_cleanup_resource;
dpmcp_dev->consumer_link = device_link_add(&mc_dev->dev, /* If the DPRC device itself tries to allocate a portal (usually for
&dpmcp_dev->dev, * UAPI interaction), don't add a device link between them since the
DL_FLAG_AUTOREMOVE_CONSUMER); * DPMCP device is an actual child device of the DPRC and a reverse
if (!dpmcp_dev->consumer_link) { * dependency is not allowed.
error = -EINVAL; */
goto error_cleanup_mc_io; 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; *new_mc_io = mc_io;