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drm/ast: Remove existing framebuffers before loading driver 

If vesafb attaches to the AST device, it configures the framebuffer memory
for uncached access by default. When ast.ko later tries to attach itself to
the device, it wants to use write-combining on the framebuffer memory, but
vesefb's existing configuration for uncached access takes precedence. This
results in reduced performance.

Removing the framebuffer's configuration before loding the AST driver fixes
the problem. Other DRM drivers already contain equivalent code.

Link: https://bugzilla.opensuse.org/show_bug.cgi?id=1112963
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: <stable@vger.kernel.org>
Tested-by: Y.C. Chen <yc_chen@aspeedtech.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Tested-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Dave Airlie <airlied@redhat.com>
hifive-unleashed-5.1
Thomas Zimmermann 2018-11-15 11:42:16 +01:00 committed by Dave Airlie
parent 9ff01193a2
commit 5478ad10e7
1 changed files with 21 additions and 0 deletions
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21
drivers/gpu/drm/ast/ast_drv.c
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@ -60,8 +60,29 @@ static const struct pci_device_id pciidlist[] = {
MODULE_DEVICE_TABLE(pci, pciidlist);
static void ast_kick_out_firmware_fb(struct pci_dev *pdev)
{
struct apertures_struct *ap;
bool primary = false;
ap = alloc_apertures(1);
if (!ap)
return;
ap->ranges[0].base = pci_resource_start(pdev, 0);
ap->ranges[0].size = pci_resource_len(pdev, 0);
#ifdef CONFIG_X86
primary = pdev->resource[PCI_ROM_RESOURCE].flags & IORESOURCE_ROM_SHADOW;
#endif
drm_fb_helper_remove_conflicting_framebuffers(ap, "astdrmfb", primary);
kfree(ap);
}
static int ast_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
{
ast_kick_out_firmware_fb(pdev);
return drm_get_pci_dev(pdev, ent, &driver);
}