[PATCH 4.9 45/63] drm/ast: Fix AST2400 POST failure without BMC FW or VBIOS

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Y.C. Chen <yc_c...@aspeedtech.com>

commit 3856081eede297b617560b85e948cfb00bb395ec upstream.

The current POST code for the AST2300/2400 family doesn't work properly
if the chip hasn't been initialized previously by either the BMC own FW
or the VBIOS. This fixes it.

Signed-off-by: Y.C. Chen <yc_c...@aspeedtech.com>
Signed-off-by: Benjamin Herrenschmidt <b...@kernel.crashing.org>
Tested-by: Y.C. Chen <yc_c...@aspeedtech.com>
Acked-by: Joel Stanley <j...@jms.id.au>
Signed-off-by: Dave Airlie <airl...@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 drivers/gpu/drm/ast/ast_post.c |   38 +++++++++++++++++++++++++++++++++++---
 1 file changed, 35 insertions(+), 3 deletions(-)

--- a/drivers/gpu/drm/ast/ast_post.c
+++ b/drivers/gpu/drm/ast/ast_post.c
@@ -1626,12 +1626,44 @@ static void ast_init_dram_2300(struct dr
                temp |= 0x73;
                ast_write32(ast, 0x12008, temp);
 
+               param.dram_freq = 396;
                param.dram_type = AST_DDR3;
+               temp = ast_mindwm(ast, 0x1e6e2070);
                if (temp & 0x01000000)
                        param.dram_type = AST_DDR2;
-               param.dram_chipid = ast->dram_type;
-               param.dram_freq = ast->mclk;
-               param.vram_size = ast->vram_size;
+                switch (temp & 0x18000000) {
+               case 0:
+                       param.dram_chipid = AST_DRAM_512Mx16;
+                       break;
+               default:
+               case 0x08000000:
+                       param.dram_chipid = AST_DRAM_1Gx16;
+                       break;
+               case 0x10000000:
+                       param.dram_chipid = AST_DRAM_2Gx16;
+                       break;
+               case 0x18000000:
+                       param.dram_chipid = AST_DRAM_4Gx16;
+                       break;
+               }
+                switch (temp & 0x0c) {
+                default:
+               case 0x00:
+                       param.vram_size = AST_VIDMEM_SIZE_8M;
+                       break;
+
+               case 0x04:
+                       param.vram_size = AST_VIDMEM_SIZE_16M;
+                       break;
+
+               case 0x08:
+                       param.vram_size = AST_VIDMEM_SIZE_32M;
+                       break;
+
+               case 0x0c:
+                       param.vram_size = AST_VIDMEM_SIZE_64M;
+                       break;
+               }
 
                if (param.dram_type == AST_DDR3) {
                        get_ddr3_info(ast, &param);