> Subject: [PATCH] bus: fsl-mc: allocate resources when there is no scan in
> progress
>
> Allocate resources from the fsl-mc bus only when a scan of the bus is not
> happening. This is useful when functional devices on the bus, such as DPNI,
> DPSW etc, request some kind of allocatable object but the scan of the bus is
> still
> in progress, thus those resources are not yet available. Catch this early and
> notify the upper layer driver of the condition.
>
> Signed-off-by: Ioana Ciornei <ioana.cior...@nxp.com>
> ---
Please don't apply this.
I just discovered a corner case in which this approach does not work.
Sorry for the bother,
Ioana
> drivers/bus/fsl-mc/fsl-mc-allocator.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/bus/fsl-mc/fsl-mc-allocator.c
> b/drivers/bus/fsl-mc/fsl-mc-
> allocator.c
> index cc7bb900f524..794ddc9589dc 100644
> --- a/drivers/bus/fsl-mc/fsl-mc-allocator.c
> +++ b/drivers/bus/fsl-mc/fsl-mc-allocator.c
> @@ -184,6 +184,9 @@ int __must_check fsl_mc_resource_allocate(struct
> fsl_mc_bus *mc_bus,
> BUILD_BUG_ON(ARRAY_SIZE(fsl_mc_pool_type_strings) !=
> FSL_MC_NUM_POOL_TYPES);
>
> + if (!mutex_trylock(&mc_bus->scan_mutex))
> + return -ENXIO;
> +
> *new_resource = NULL;
> if (pool_type < 0 || pool_type >= FSL_MC_NUM_POOL_TYPES)
> goto out;
> @@ -197,7 +200,7 @@ int __must_check fsl_mc_resource_allocate(struct
> fsl_mc_bus *mc_bus,
> struct fsl_mc_resource, node);
>
> if (!resource) {
> - error = -ENXIO;
> + error = -ENOMEM;
> dev_err(&mc_bus_dev->dev,
> "No more resources of type %s left\n",
> fsl_mc_pool_type_strings[pool_type]);
> @@ -220,6 +223,7 @@ int __must_check fsl_mc_resource_allocate(struct
> fsl_mc_bus *mc_bus,
> mutex_unlock(&res_pool->mutex);
> *new_resource = resource;
> out:
> + mutex_unlock(&mc_bus->scan_mutex);
> return error;
> }
> EXPORT_SYMBOL_GPL(fsl_mc_resource_allocate);
> --
> 2.17.1
