hwrng: amd - Revert managed API changes

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commit 69db700931 upstream.

After commit 31b2a73c9c ("hwrng: amd - Migrate to managed API"), the
amd-rng driver uses devres with pci_dev->dev to keep track of resources,
but does not actually register a PCI driver.  This results in the
following issues:

1. The message

WARNING: CPU: 2 PID: 621 at drivers/base/dd.c:349 driver_probe_device+0x38c

is output when the i2c_amd756 driver loads and attempts to register a PCI
driver.  The PCI & device subsystems assume that no resources have been
registered for the device, and the WARN_ON() triggers since amd-rng has
already do so.

2.  The driver leaks memory because the driver does not attach to a
device.  The driver only uses the PCI device as a reference.   devm_*()
functions will release resources on driver detach, which the amd-rng
driver will never do.  As a result,

3.  The driver cannot be reloaded because there is always a use of the
ioport and region after the first load of the driver.

Revert the changes made by 31b2a73c9c ("hwrng: amd - Migrate to managed
API").

Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Fixes: 31b2a73c9c ("hwrng: amd - Migrate to managed API").
Cc: Matt Mackall <mpm@selenic.com>
Cc: Corentin LABBE <clabbe.montjoie@gmail.com>
Cc: PrasannaKumar Muralidharan <prasannatsmkumar@gmail.com>
Cc: Wei Yongjun <weiyongjun1@huawei.com>
Cc: linux-crypto@vger.kernel.org
Cc: linux-geode@lists.infradead.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

...

This commit is contained in:

Prarit Bhargava 2017-03-14 07:36:01 -04:00 • committed by Greg Kroah-Hartman

parent 0d69a88041

commit 5d6f7b3611

1 changed files with 34 additions and 8 deletions

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drivers/char/hw_random/amd-rng.c

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