# --- T2-COPYRIGHT-BEGIN ---
# t2/package/*/linux/hotfix-ppc-isa-dma.patch
# Copyright (C) 2025 The T2 SDE Project
# SPDX-License-Identifier: GPL-2.0 or patched project license
# --- T2-COPYRIGHT-END ---

ALSA pcmC0D0p,0:CS4236: cannot preallocate for size 65536
ALSA pcmC0D0c,0:CS4236: cannot preallocate for size 65536

Use ZONE_DMA for 24-bit, 16MB ISA DMA like alpha or x86,
and ZONE_DMA32 for 31-bit PowerMac Broadcom hacks.

--- linux-6.15/arch/powerpc/mm/mem.c.vanilla	2025-07-10 13:02:38.333694091 +0200
+++ linux-6.15/arch/powerpc/mm/mem.c	2025-07-10 13:33:08.853860359 +0200
@@ -260,7 +260,11 @@
 	zone_dma_limit = DMA_BIT_MASK(zone_dma_bits);
 
 #ifdef CONFIG_ZONE_DMA
-	max_zone_pfns[ZONE_DMA]	= min(max_low_pfn,
+	/* 24-bit, 16MB ISA DMA */
+	max_zone_pfns[ZONE_DMA]	= 1UL << (24 - PAGE_SHIFT);
+#endif
+#ifdef CONFIG_ZONE_DMA32
+	max_zone_pfns[ZONE_DMA32] = min(max_low_pfn,
 				      1UL << (zone_dma_bits - PAGE_SHIFT));
 #endif
 	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
--- linux-6.15/arch/powerpc/platforms/chrp/Kconfig.vanilla	2025-07-10 13:01:24.629970059 +0200
+++ linux-6.15/arch/powerpc/platforms/chrp/Kconfig	2025-07-10 13:36:51.939828805 +0200
@@ -13,4 +13,5 @@
 	select PPC_UDBG_16550
 	select PPC_HASH_MMU_NATIVE
 	select FORCE_PCI
+	select ZONE_DMA
 	default y
--- linux-6.15/arch/powerpc/platforms/powermac/Kconfig.vanilla	2025-07-10 13:01:12.426792180 +0200
+++ linux-6.15/arch/powerpc/platforms/powermac/Kconfig	2025-07-10 13:31:09.797916612 +0200
@@ -9,7 +9,7 @@
 	select PPC_MPC106 if PPC32
 	select PPC_64S_HASH_MMU if PPC64
 	select PPC_HASH_MMU_NATIVE
-	select ZONE_DMA if PPC32
+	select ZONE_DMA32 if PPC32
 	default y
 
 config PPC_PMAC64
--- linux-6.15/arch/powerpc/platforms/Kconfig.cputype.vanilla	2025-07-10 13:00:48.560083125 +0200
+++ linux-6.15/arch/powerpc/platforms/Kconfig.cputype	2025-07-10 13:30:56.239587297 +0200
@@ -101,7 +101,7 @@
 	select PPC_FPU # Make it a choice ?
 	select PPC_SMP_MUXED_IPI
 	select PPC_DOORBELL
-	select ZONE_DMA
+	select ZONE_DMA32
 
 endchoice