4.19-stable review patch. If anyone has any objections, please let me know.
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From: Thomas Zimmermann tzimmermann@suse.de
commit 5478ad10e7850ce3d8b7056db05ddfa3c9ddad9a upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/gpu/drm/ast/ast_drv.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+)
--- a/drivers/gpu/drm/ast/ast_drv.c +++ b/drivers/gpu/drm/ast/ast_drv.c @@ -60,8 +60,29 @@ static const struct pci_device_id pciidl
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); }