[Why] Similar to commit <298360af3> ast_init_dram_reg() configures a window in order to access BMC memory. A BMC register can be configured to disallow this, and if so, causes an infinite loop in the ast driver which renders the system unusable. [How] Fix this by erroring out if an error is detected.
Signed-off-by: Defang Bo bodefang@126.com --- drivers/gpu/drm/ast/ast_post.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/ast/ast_post.c b/drivers/gpu/drm/ast/ast_post.c index ef19c70..86e4d23 100644 --- a/drivers/gpu/drm/ast/ast_post.c +++ b/drivers/gpu/drm/ast/ast_post.c @@ -302,13 +302,13 @@ static void ast_init_dram_reg(struct drm_device *dev) ast_write32(ast, 0x12000, 0x1688A8A8); do { if (pci_channel_offline(dev->pdev)) - return -EIO; + return -EIO; } while (ast_read32(ast, 0x12000) != 0x01);
ast_write32(ast, 0x10000, 0xfc600309); do { if (pci_channel_offline(dev->pdev)) - return -EIO; + return -EIO; } while (ast_read32(ast, 0x10000) != 0x01); }