[PATCH] mach-snapdragon: do carveouts for qcs404 only

[Sam Day]

The newly introduced carve_out_reserved_memory causes issues when
U-Boot is chained from the lk2nd bootloader. lk2nd provides a
simple-framebuffer device and marks the framebuffer region as no-map in
the supplied /reserved-memory. Consequently, the simple_video driver
triggers a page fault when it tries to write to this region.

As per Caleb's advice, this simple patch only does the carveouts for the
qcs404 SoC for which it was originally designed. The intent is to do the
carveouts for more Qualcomm SoCs in future.

---
I'm not sure if it's feasible to get this in for the 2024.07 release,
but it'd be great if we could - it's the only thing that breaks U-Boot
master on msm8916 devices that chain from lk2nd.

Signed-off-by: Sam Day <me at samcday.com>
---
 arch/arm/mach-snapdragon/board.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/arch/arm/mach-snapdragon/board.c b/arch/arm/mach-snapdragon/board.c
index 3d5994c878..b439a19ec7 100644
--- a/arch/arm/mach-snapdragon/board.c
+++ b/arch/arm/mach-snapdragon/board.c
@@ -467,10 +467,12 @@ void enable_caches(void)
 	gd->arch.tlb_addr = tlb_addr;
 	gd->arch.tlb_size = tlb_size;
 
-	carveout_start = get_timer(0);
-	/* Takes ~20-50ms on SDM845 */
-	carve_out_reserved_memory();
-	debug("carveout time: %lums\n", get_timer(carveout_start));
-
+	/* We do the carveouts only for QCS404, for now. */
+	if (fdt_node_check_compatible(gd->fdt_blob, 0, "qcom,qcs404") == 0) {
+		carveout_start = get_timer(0);
+		/* Takes ~20-50ms on SDM845 */
+		carve_out_reserved_memory();
+		debug("carveout time: %lums\n", get_timer(carveout_start));
+	}
 	dcache_enable();
 }

---
base-commit: 1c40dda60f5f7e83a6d6f541cf5a57eb7e8ec43c
change-id: 20240507-qcs404-carveout-only-7a15bbf3fd89

Best regards,
-- 
Sam Day <me at samcday.com>