From: Jammy Huang <jammy_huang@xxxxxxxxxxxxxx> [ Upstream commit 4327a6137ed43a091d900b1ac833345d60f32228 ] ARM architecture only has 'memory', so all devices are accessed by MMIO if possible. Signed-off-by: Jammy Huang <jammy_huang@xxxxxxxxxxxxxx> Reviewed-by: Thomas Zimmermann <tzimmermann@xxxxxxx> Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20230421003354.27767-1-jammy_huang@xxxxxxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/gpu/drm/ast/ast_main.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/ast/ast_main.c b/drivers/gpu/drm/ast/ast_main.c index 067453266897f..5df527051177a 100644 --- a/drivers/gpu/drm/ast/ast_main.c +++ b/drivers/gpu/drm/ast/ast_main.c @@ -427,11 +427,12 @@ struct ast_private *ast_device_create(const struct drm_driver *drv, return ERR_PTR(-EIO); /* - * If we don't have IO space at all, use MMIO now and - * assume the chip has MMIO enabled by default (rev 0x20 - * and higher). + * After AST2500, MMIO is enabled by default, and it should be adopted + * to be compatible with Arm. */ - if (!(pci_resource_flags(pdev, 2) & IORESOURCE_IO)) { + if (pdev->revision >= 0x40) { + ast->ioregs = ast->regs + AST_IO_MM_OFFSET; + } else if (!(pci_resource_flags(pdev, 2) & IORESOURCE_IO)) { drm_info(dev, "platform has no IO space, trying MMIO\n"); ast->ioregs = ast->regs + AST_IO_MM_OFFSET; } -- 2.39.2
