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| author | Ioana Ciornei <ioana.ciornei@nxp.com> | 2025-04-08 13:58:10 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-06-27 11:07:28 +0100 |
| commit | 03477f707b48a0e029010d718740b086823aa025 (patch) | |
| tree | c7336cfea1c70877a3bebb0d4de93ca44771f329 /drivers/bus | |
| parent | 8212cd92fe40aae6fe5a073bc70e758c42bb4bfc (diff) | |
| download | linux-03477f707b48a0e029010d718740b086823aa025.tar.gz linux-03477f707b48a0e029010d718740b086823aa025.tar.bz2 linux-03477f707b48a0e029010d718740b086823aa025.zip | |
bus: fsl-mc: do not add a device-link for the UAPI used DPMCP device
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: afb77422819f ("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>
Diffstat (limited to 'drivers/bus')
| -rw-r--r-- | drivers/bus/fsl-mc/mc-io.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/drivers/bus/fsl-mc/mc-io.c b/drivers/bus/fsl-mc/mc-io.c index 95b10a6cf307..8b7a34f4db94 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; |