Re: [PATCH] drm/ast: Fix ARM compatibility

From: Thomas Zimmermann
Date: Mon Apr 17 2023 - 07:52:44 EST


Hi

Am 07.04.23 um 04:09 schrieb Jammy Huang:
Hi Thomas,

Could you help review this patch??

We met some problem on nvidia's ARM platfrom and need this patch to fix it.

On 2023/3/2 上午 10:19, Jammy Huang wrote:
ARM architecture only has 'memory', so all devices are accessed by MMIO.

Signed-off-by: Jammy Huang <jammy_huang@xxxxxxxxxxxxxx>
---
  drivers/gpu/drm/ast/ast_main.c | 17 +----------------
  1 file changed, 1 insertion(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/ast/ast_main.c b/drivers/gpu/drm/ast/ast_main.c
index 794ffd4a29c5..f86d01e9f024 100644
--- a/drivers/gpu/drm/ast/ast_main.c
+++ b/drivers/gpu/drm/ast/ast_main.c
@@ -424,22 +424,7 @@ struct ast_device *ast_device_create(const struct drm_driver *drv,
      if (!ast->regs)
          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).
-     */
-    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;
-    }
-
-    /* "map" IO regs if the above hasn't done so already */
-    if (!ast->ioregs) {
-        ast->ioregs = pcim_iomap(pdev, 2, 0);

What happens on systems that use this branch?

Best regards
Thomas

-        if (!ast->ioregs)
-            return ERR_PTR(-EIO);
-    }
+    ast->ioregs = ast->regs + AST_IO_MM_OFFSET;
      ast_detect_chip(dev, &need_post);

base-commit: 254986e324add8a30d0019c6da59f81adc8b565f


--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Ivo Totev

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