From 6c5ba2d3c4f06793dc27711e2d8ebb8968946d87 Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@suse.de>
Date: Wed, 21 Apr 2021 13:12:48 +0200
Subject: [PATCH 02/11] drm/ast: Keep MISC fields when enabling VGA
Patch-mainline: Never, temporary fixes until upstream resolution
References: bsc#1174416
A code snippet forward-ported from A-Speed downstream driver.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
drivers/gpu/drm/ast/ast_post.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/ast/ast_post.c b/drivers/gpu/drm/ast/ast_post.c
index c043fe717553..6423d08afd8a 100644
--- a/drivers/gpu/drm/ast/ast_post.c
+++ b/drivers/gpu/drm/ast/ast_post.c
@@ -40,9 +40,11 @@ static void ast_post_chip_2500(struct drm_device *dev);
void ast_enable_vga(struct drm_device *dev)
{
struct ast_private *ast = to_ast_private(dev);
+ u8 ch;
ast_io_write8(ast, AST_IO_VGA_ENABLE_PORT, 0x01);
- ast_io_write8(ast, AST_IO_MISC_PORT_WRITE, 0x01);
+ ch = ast_io_read8(ast, AST_IO_MISC_PORT_READ);
+ ast_io_write8(ast, AST_IO_MISC_PORT_WRITE, ch | 0x01);
}
void ast_enable_mmio(struct drm_device *dev)
--
2.26.2