[PATCH AUTOSEL 4.19 24/27] drm/ast: Fixed reboot test may cause system hanged

Sasha Levin
2019-08-20T13:43:01Z

From: "Y.C. Chen" <yc_chen@aspeedtech.com>

[ 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>
---
drivers/gpu/drm/ast/ast_main.c | 5 ++++-
drivers/gpu/drm/ast/ast_mode.c | 2 +-
drivers/gpu/drm/ast/ast_post.c | 2 +-
3 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/ast/ast_main.c b/drivers/gpu/drm/ast/ast_main.c
index 373700c05a00f..224fa1ef87ff9 100644
--- 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 8bb355d5d43d8..9d92d2d2fcfc7 100644
--- 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 f7d421359d564..c1d1ac51d1c20 100644
--- 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);
}

--
2.20.1