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Message-Id: <20230520182215.845131-1-sashal@kernel.org>
Date: Sat, 20 May 2023 14:22:04 -0400
From: Sasha Levin <sashal@...nel.org>
To: linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc: Jammy Huang <jammy_huang@...eedtech.com>,
Thomas Zimmermann <tzimmermann@...e.de>,
Sasha Levin <sashal@...nel.org>, airlied@...hat.com,
airlied@...il.com, daniel@...ll.ch, dri-devel@...ts.freedesktop.org
Subject: [PATCH AUTOSEL 5.15 01/11] drm/ast: Fix ARM compatibility
From: Jammy Huang <jammy_huang@...eedtech.com>
[ Upstream commit 4327a6137ed43a091d900b1ac833345d60f32228 ]
ARM architecture only has 'memory', so all devices are accessed by
MMIO if possible.
Signed-off-by: Jammy Huang <jammy_huang@...eedtech.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@...e.de>
Signed-off-by: Thomas Zimmermann <tzimmermann@...e.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20230421003354.27767-1-jammy_huang@aspeedtech.com
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
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 79a3618679554..754a08c92d3d1 100644
--- a/drivers/gpu/drm/ast/ast_main.c
+++ b/drivers/gpu/drm/ast/ast_main.c
@@ -423,11 +423,12 @@ 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
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