From 0dd68309b9c516eac76549b71f68f01f57bb0c71 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Thu, 4 Sep 2014 17:44:18 +1000 Subject: drm/ast: Try to use MMIO registers when PIO isn't supported If the PIO resources haven't been assigned, then we have no choice but try to use the MMIO version. This is the case for example on POWER8 which doesn't support PIO at all. Chips rev 0x20 or later have MMIO decoding enabled by default. Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Dave Airlie --- drivers/gpu/drm/ast/ast_main.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) (limited to 'drivers/gpu/drm/ast/ast_main.c') diff --git a/drivers/gpu/drm/ast/ast_main.c b/drivers/gpu/drm/ast/ast_main.c index a2cc6be97983..c2ff7933a90e 100644 --- a/drivers/gpu/drm/ast/ast_main.c +++ b/drivers/gpu/drm/ast/ast_main.c @@ -359,10 +359,24 @@ int ast_driver_load(struct drm_device *dev, unsigned long flags) ret = -EIO; goto out_free; } - ast->ioregs = pci_iomap(dev->pdev, 2, 0); + + /* + * 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). + */ + if (!(pci_resource_flags(dev->pdev, 2) & IORESOURCE_IO)) { + DRM_INFO("platform has no IO space, trying MMIO\n"); + ast->ioregs = ast->regs + AST_IO_MM_OFFSET; + } + + /* "map" IO regs if the above hasn't done so already */ if (!ast->ioregs) { - ret = -EIO; - goto out_free; + ast->ioregs = pci_iomap(dev->pdev, 2, 0); + if (!ast->ioregs) { + ret = -EIO; + goto out_free; + } } ast_detect_chip(dev); -- cgit v1.2.3-59-g8ed1b