[PATCH 1/2] hw/misc/bcm2835_property: Fix framebuffer with recent RPi kernels

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

The framebuffer driver fails to initialize with recent Raspberry Pi
kernels, such as the ones shipped in the current RaspiOS images
(with the out of tree bcm2708_fb.c driver)

The reason is that this driver uses a new firmware call to query the
number of displays, and the fallback when this call fails is broken.

So implement the call and claim we have exactly one display

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
 hw/misc/bcm2835_property.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/hw/misc/bcm2835_property.c b/hw/misc/bcm2835_property.c
index 73941bdae9..b958fa6a5c 100644
--- a/hw/misc/bcm2835_property.c
+++ b/hw/misc/bcm2835_property.c
@@ -269,6 +269,10 @@ static void bcm2835_property_mbox_push(BCM2835PropertyState *s, uint32_t value)
             stl_le_phys(&s->dma_as, value + 12, 0);
             resplen = 4;
             break;
+        case 0x00040013: /* Get num displays */
+            stl_le_phys(&s->dma_as, value + 12, 1);
+            resplen = 4;
+            break;
 
         case 0x00060001: /* Get DMA channels */
             /* channels 2-5 */