[RFC PATCH 2/3] drm/imagination: fix clock control on the J722S
Michael Walle
mwalle at kernel.org
Wed Jul 16 06:47:16 PDT 2025
The J722S won't let you set the clock frequency if there is no device
using it. Thus, the assigned-clocks property won't work per se.
As a workaround, set the clock again during the probing of the driver.
Signed-off-by: Michael Walle <mwalle at kernel.org>
---
drivers/gpu/drm/imagination/pvr_device.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/gpu/drm/imagination/pvr_device.c b/drivers/gpu/drm/imagination/pvr_device.c
index 8b9ba4983c4c..e7a7cc1bdf93 100644
--- a/drivers/gpu/drm/imagination/pvr_device.c
+++ b/drivers/gpu/drm/imagination/pvr_device.c
@@ -16,6 +16,7 @@
#include <linux/bitfield.h>
#include <linux/clk.h>
+#include <linux/clk/clk-conf.h>
#include <linux/compiler_attributes.h>
#include <linux/compiler_types.h>
#include <linux/dma-mapping.h>
@@ -641,6 +642,14 @@ pvr_device_init(struct pvr_device *pvr_dev)
if (err)
return err;
+ /* Set any 'assigned-clocks' properties again. This is a workaround for
+ * the clock handling on k3 platforms. There, one cannot set the clock
+ * frequency until there is at least one (enabled) user if it.
+ */
+ err = of_clk_set_defaults(drm_dev->dev->of_node, true);
+ if (err)
+ return err;
+
/* Map the control registers into memory. */
err = pvr_device_reg_init(pvr_dev);
if (err)
--
2.39.5
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