On Thu May 21 00:44:31 2026 +0200, Sven Püschel wrote:
> Disable multi-core support in preparation of the RGA3 addition. The
> RK3588 SoC features two equal RGA3 cores. This allows scheduling of the
> work between both cores, which is not yet implemented. Until it is
> implemented avoid exposing both cores as independent video devices to
> prevent an ABI breakage when multi-core support is added.
>
> This patch is copied from the Hantro driver patch to disable multi core
> support by Sebastian Reichel. See
> commit ccdeb8d57f7f ("media: hantro: Disable multicore support")
>
> Link:
> https://lore.kernel.org/all/[email protected]/
> Reviewed-by: Nicolas Dufresne <[email protected]>
> Signed-off-by: Sven Püschel <[email protected]>
> Signed-off-by: Nicolas Dufresne <[email protected]>
> Signed-off-by: Hans Verkuil <[email protected]>
Patch committed.
Thanks,
Hans Verkuil
drivers/media/platform/rockchip/rga/rga.c | 47 +++++++++++++++++++++++++++++++
1 file changed, 47 insertions(+)
---
diff --git a/drivers/media/platform/rockchip/rga/rga.c
b/drivers/media/platform/rockchip/rga/rga.c
index 8d60e94da32d..0152b8ef2da2 100644
--- a/drivers/media/platform/rockchip/rga/rga.c
+++ b/drivers/media/platform/rockchip/rga/rga.c
@@ -711,6 +711,49 @@ static int rga_parse_dt(struct rockchip_rga *rga)
return 0;
}
+/*
+ * Some SoCs, like RK3588 have multiple identical RGA3 cores, but the
+ * kernel is currently missing support for multi-core handling. Exposing
+ * separate devices for each core to userspace is bad, since that does
+ * not allow scheduling tasks properly (and creates ABI). With this workaround
+ * the driver will only probe for the first core and early exit for the other
+ * cores. Once the driver gains multi-core support, the same technique
+ * for detecting the main core can be used to cluster all cores together.
+ */
+static int rga_disable_multicore(struct device *dev)
+{
+ struct device_node *node = NULL;
+ const char *compatible;
+ bool is_main_core;
+ int ret;
+
+ /* Intentionally ignores the fallback strings */
+ ret = of_property_read_string(dev->of_node, "compatible", &compatible);
+ if (ret)
+ return ret;
+
+ /* The first compatible and available node found is considered the main
core */
+ do {
+ node = of_find_compatible_node(node, NULL, compatible);
+ if (of_device_is_available(node))
+ break;
+ } while (node);
+
+ if (!node)
+ return -EINVAL;
+
+ is_main_core = (dev->of_node == node);
+
+ of_node_put(node);
+
+ if (!is_main_core) {
+ dev_info(dev, "missing multi-core support, ignoring this
instance\n");
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
static int rga_probe(struct platform_device *pdev)
{
struct rockchip_rga *rga;
@@ -721,6 +764,10 @@ static int rga_probe(struct platform_device *pdev)
if (!pdev->dev.of_node)
return -ENODEV;
+ ret = rga_disable_multicore(&pdev->dev);
+ if (ret)
+ return ret;
+
rga = devm_kzalloc(&pdev->dev, sizeof(*rga), GFP_KERNEL);
if (!rga)
return -ENOMEM;
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