Messages in this thread |  | | Date | Sun, 25 Dec 2022 00:03:38 +0200 | From | Péter Ujfalusi <> | Subject | Re: [PATCH] soc: ti: k3-ringacc: Add try_module_get() to k3_dmaring_request_dual_ring() |
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Hi Nicolas,
On 21/12/2022 22:05, Nicolas Frayer wrote: > When the k3 ring accelerator driver has been modified to add module build > support, try_module_get() and module_put() have been added to update the > module refcnt. One code path has not been updated and it has introduced > an issue where the refcnt is decremented by module_put() in > k3_ringacc_ring_free() without being incremented previously. > Adding try_module_get() to k3_dmaring_request_dual_ring() ensures the > refcnt is kept up to date.
Good catch! I had never had my hands on a device with DMSS (BCDMA/PKDMA) and the original module support was developed and tested on devices with UDMA.
can you add the fixes tag along with my reviewed by tag?
Fixes: c07f216a8b72 ("soc: ti: k3-ringacc: Allow the driver to be built as module") Reviewed-by: Peter Ujfalusi <peter.ujfalusi@gmail.com>
> > Signed-off-by: Nicolas Frayer <nfrayer@baylibre.com> > --- > drivers/soc/ti/k3-ringacc.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/soc/ti/k3-ringacc.c b/drivers/soc/ti/k3-ringacc.c > index e01e4d815230a..8f131368a7586 100644 > --- a/drivers/soc/ti/k3-ringacc.c > +++ b/drivers/soc/ti/k3-ringacc.c > @@ -406,6 +406,11 @@ static int k3_dmaring_request_dual_ring(struct k3_ringacc *ringacc, int fwd_id, > > mutex_lock(&ringacc->req_lock); > > + if (!try_module_get(ringacc->dev->driver->owner)) { > + ret = -EINVAL; > + goto err_module_get; > + } > + > if (test_bit(fwd_id, ringacc->rings_inuse)) { > ret = -EBUSY; > goto error; > @@ -421,6 +426,8 @@ static int k3_dmaring_request_dual_ring(struct k3_ringacc *ringacc, int fwd_id, > return 0; > > error: > + module_put(ringacc->dev->driver->owner); > +err_module_get: > mutex_unlock(&ringacc->req_lock); > return ret; > }
-- Péter
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