drm/ast: Fixed reboot test may cause system hanged

[ Upstream commit 05b439711f6ff8700e8660f97a1179650778b9cb ]

There is another thread still access standard VGA I/O while loading drm driver.
Disable standard VGA I/O decode to avoid this issue.

Signed-off-by: Y.C. Chen <yc_chen@aspeedtech.com>
Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1523410059-18415-1-git-send-email-yc_chen@aspeedtech.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/ast/ast_main.c b/drivers/gpu/drm/ast/ast_main.c
index 373700c05a00f9f3890d48fee79317edf77cedd8..224fa1ef87ff92125c5ada667f41c0defac43e86 100644 (file)
--- a/drivers/gpu/drm/ast/ast_main.c
+++ b/drivers/gpu/drm/ast/ast_main.c
@@ -131,8 +131,8 @@ static int ast_detect_chip(struct drm_device *dev, bool *need_post)
 
 
        /* Enable extended register access */
-       ast_enable_mmio(dev);
        ast_open_key(ast);
+       ast_enable_mmio(dev);
 
        /* Find out whether P2A works or whether to use device-tree */
        ast_detect_config_mode(dev, &scu_rev);
@@ -576,6 +576,9 @@ void ast_driver_unload(struct drm_device *dev)
 {
        struct ast_private *ast = dev->dev_private;
 
+       /* enable standard VGA decode */
+       ast_set_index_reg(ast, AST_IO_CRTC_PORT, 0xa1, 0x04);
+
        ast_release_firmware(dev);
        kfree(ast->dp501_fw_addr);
        ast_mode_fini(dev);

diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c
index 343867b182dd8f633710ee066124e058d4056ac4..a09fafa2708224141678a61863ce26e22f07fe5e 100644 (file)
--- a/drivers/gpu/drm/ast/ast_mode.c
+++ b/drivers/gpu/drm/ast/ast_mode.c
@@ -600,7 +600,7 @@ static int ast_crtc_mode_set(struct drm_crtc *crtc,
                return -EINVAL;
        ast_open_key(ast);
 
-       ast_set_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xa1, 0xff, 0x04);
+       ast_set_index_reg(ast, AST_IO_CRTC_PORT, 0xa1, 0x06);
 
        ast_set_std_reg(crtc, adjusted_mode, &vbios_mode);
        ast_set_crtc_reg(crtc, adjusted_mode, &vbios_mode);

diff --git a/drivers/gpu/drm/ast/ast_post.c b/drivers/gpu/drm/ast/ast_post.c
index f7d421359d564756ff86d78c64293e37eea74c7e..c1d1ac51d1c207c0cb0b2f08825aa19ca7761bde 100644 (file)
--- a/drivers/gpu/drm/ast/ast_post.c
+++ b/drivers/gpu/drm/ast/ast_post.c
@@ -46,7 +46,7 @@ void ast_enable_mmio(struct drm_device *dev)
 {
        struct ast_private *ast = dev->dev_private;
 
-       ast_set_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xa1, 0xff, 0x04);
+       ast_set_index_reg(ast, AST_IO_CRTC_PORT, 0xa1, 0x06);
 }