On Sat, Oct 14, 2023 at 04:15:47PM -0700, Tanmay Shah wrote:
> From: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
>
> Multi-cluster remoteproc designs typically have the following DT
> declaration:
>
> remoteproc_cluster {
> compatible = "soc,remoteproc-cluster";
>
> core0: core0 {
> compatible = "soc,remoteproc-core"
> memory-region;
> sram;
> };
>
> core1: core1 {
> compatible = "soc,remoteproc-core"
> memory-region;
> sram;
> }
> };
>
> A driver exists for the cluster rather than the individual cores
> themselves so that operation mode and HW specific configurations
> applicable to the cluster can be made.
>
> Because the driver exists at the cluster level and not the individual
> core level, function rproc_get_by_phandle() fails to return the
> remoteproc associated with the phandled it is called for.
>
> This patch enhances rproc_get_by_phandle() by looking for the cluster's
> driver when the driver for the immediate remoteproc's parent is not
> found.
>
> Reported-by: Ben Levinsky <ben.levinsky@xxxxxxxxxx>
> Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
> Tested-by: Ben Levinsky <ben.levinsky@xxxxxxx>
> ---
> drivers/remoteproc/remoteproc_core.c | 28 +++++++++++++++++++++++++++-
> 1 file changed, 27 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> index 695cce218e8c..3a8191803885 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -33,6 +33,7 @@
> #include <linux/idr.h>
> #include <linux/elf.h>
> #include <linux/crc32.h>
> +#include <linux/of_platform.h>
> #include <linux/of_reserved_mem.h>
> #include <linux/virtio_ids.h>
> #include <linux/virtio_ring.h>
> @@ -2111,7 +2112,9 @@ EXPORT_SYMBOL(rproc_detach);
> #ifdef CONFIG_OF
> struct rproc *rproc_get_by_phandle(phandle phandle)
> {
> + struct platform_device *cluster_pdev;
> struct rproc *rproc = NULL, *r;
> + struct device_driver *driver;
> struct device_node *np;
>
> np = of_find_node_by_phandle(phandle);
> @@ -2122,7 +2125,30 @@ struct rproc *rproc_get_by_phandle(phandle phandle)
> list_for_each_entry_rcu(r, &rproc_list, node) {
> if (r->dev.parent && device_match_of_node(r->dev.parent, np)) {
> /* prevent underlying implementation from being removed */
> - if (!try_module_get(r->dev.parent->driver->owner)) {
> +
> + /*
> + * If the remoteproc's parent has a driver, the
> + * remoteproc is not part of a cluster and we can use
> + * that driver.
> + */
> + driver = r->dev.parent->driver;
> +
> + /*
> + * If the remoteproc's parent does not have a driver,
> + * look for the driver associated with the cluster.
> + */
> + if (!driver) {
> + cluster_pdev = of_find_device_by_node(np->parent);
Both the Ti and Xilinx drivers are using of_platform_populate(), so
their r->dev.parent should have a parent reference to the cluster
device.
Unless I'm reading the code wrong, I think we should follow that
pointer, rather than taking the detour in the DeviceTree data.
Regards,
Bjorn
> + if (!cluster_pdev) {
> + dev_err(&r->dev, "can't get parent\n");
> + break;
> + }
> +
> + driver = cluster_pdev->dev.driver;
> + put_device(&cluster_pdev->dev);
> + }
> +
> + if (!try_module_get(driver->owner)) {
> dev_err(&r->dev, "can't get owner\n");
> break;
> }
> --
> 2.25.1
>
