Re: [PATCH 12/15] drm/ast: Gen4: Fix open-coded register access

[Jocelyn Falempe]

On 23/03/2026 16:56, Thomas Zimmermann wrote:

Replace all open-coded access to MCR and SCU registers in Gen4 with the
appropriate calls to ast_moutdwm() and ast_mindwm(). Use MCR and SCU
register constants. Name variables according to registers.

Thanks, it looks good to me.

Reviewed-by: Jocelyn Falempe <jfale...@redhat.com>

Signed-off-by: Thomas Zimmermann <tzimmerm...@suse.de>
---
  drivers/gpu/drm/ast/ast_2300.c | 24 +++++++++---------------
  drivers/gpu/drm/ast/ast_reg.h  |  1 +
  2 files changed, 10 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/ast/ast_2300.c b/drivers/gpu/drm/ast/ast_2300.c
index 96d9909d942c..cbeac6990c27 100644
--- a/drivers/gpu/drm/ast/ast_2300.c
+++ b/drivers/gpu/drm/ast/ast_2300.c
@@ -1245,22 +1245,15 @@ static void ast_post_chip_2300(struct ast_device *ast)

reg = ast_get_index_reg_mask(ast, AST_IO_VGACRI, 0xd0, 0xff);

        if ((reg & 0x80) == 0) {/* vga only */
-               ast_write32(ast, 0xf004, AST_REG_MCR00);
-               ast_write32(ast, 0xf000, 0x1);
-               ast_write32(ast, 0x12000, 0x1688a8a8);
-               do {
-                       ;
-               } while (ast_read32(ast, 0x12000) != 0x1);
+               u32 scu008, scu040;

- ast_write32(ast, 0x10000, 0xfc600309);

-               do {
-                       ;
-               } while (ast_read32(ast, 0x10000) != 0x1);
+               ast_moutdwm_poll(ast, AST_REG_SCU000, 
AST_REG_SCU000_PROTECTION_KEY, 0x01);
+               ast_moutdwm_poll(ast, AST_REG_MCR00, 
AST_REG_MCR00_PROTECTION_KEY, 0x01);

/* Slow down CPU/AHB CLK in VGA only mode */

-               temp = ast_read32(ast, 0x12008);
-               temp |= 0x73;
-               ast_write32(ast, 0x12008, temp);
+               scu008 = ast_mindwm(ast, AST_REG_SCU008);
+               scu008 |= 0x00000073;
+               ast_moutdwm(ast, AST_REG_SCU008, scu008);

param.dram_freq = 396;

                param.dram_type = AST_DDR3;
@@ -1306,8 +1299,9 @@ static void ast_post_chip_2300(struct ast_device *ast)
                        ddr2_init(ast, &param);
                }

- temp = ast_mindwm(ast, AST_REG_SCU040);

-               ast_moutdwm(ast, AST_REG_SCU040, temp | 0x40);
+               scu040 = ast_mindwm(ast, AST_REG_SCU040);
+               scu040 |= 0x00000040;
+               ast_moutdwm(ast, AST_REG_SCU040, scu040);
        }

/* wait ready */

diff --git a/drivers/gpu/drm/ast/ast_reg.h b/drivers/gpu/drm/ast/ast_reg.h
index 9ebdbbde9a47..c3473cad4545 100644
--- a/drivers/gpu/drm/ast/ast_reg.h
+++ b/drivers/gpu/drm/ast/ast_reg.h
@@ -183,6 +183,7 @@
  #define AST_REG_SCU(__offset)                 (AST_REG_SCU_BASE + (__offset))
  #define AST_REG_SCU000                                AST_REG_SCU(0x000)
  #define AST_REG_SCU000_PROTECTION_KEY         (0x1688a8a8)
+#define AST_REG_SCU008                         AST_REG_SCU(0x008)
  #define AST_REG_SCU00C                                AST_REG_SCU(0x00c)
  #define AST_REG_SCU020                                AST_REG_SCU(0x020)
  #define AST_REG_SCU040                                AST_REG_SCU(0x040)