Re: [PATCH v3 2/6] LoongArch/PCI: Refresh screen_info after resource assignment

[Thomas Zimmermann <tzimmermann@suse.de>]

Hi

Am 10.11.26 um 09:56 schrieb wuqianhai@loongson.cn:
> From: wuqianhai <wuqianhai@loongson.cn>
>
> PCI resource assignment runs from acpi_init() at subsys_initcall time.
> The firmware framebuffer BAR can be relocated, leaving screen_info's
> lfb_base stale.  vga_arb_device_init() runs later at subsys_initcall_sync
> time and reads screen_info to identify the firmware default VGA device.
>
> Update screen_info through the generic screen_info_apply_fixups() helper
> right after the root bus resources have been assigned, so both the VGA
> arbiter and sysfb_init() observe the final framebuffer address.

I don't know much about the internals of the PCI subsystem.  But I would 
assume that there's a common function that sets up PCI resources on all 
architectures. And this is the place where we'd want to call 
screen_info_apply_fixups().

Best regards
Thomas


>
> Signed-off-by: wuqianhai <wuqianhai@loongson.cn>
> ---
>   arch/loongarch/pci/acpi.c | 4 ++++
>   1 file changed, 4 insertions(+)
>
> diff --git a/arch/loongarch/pci/acpi.c b/arch/loongarch/pci/acpi.c
> index ccbcea61fcd9..cb313ff67f7e 100644
> --- a/arch/loongarch/pci/acpi.c
> +++ b/arch/loongarch/pci/acpi.c
> @@ -9,6 +9,7 @@
>   #include <linux/slab.h>
>   #include <linux/pci-acpi.h>
>   #include <linux/pci-ecam.h>
> +#include <linux/screen_info.h>
>   
>   #include <asm/pci.h>
>   #include <asm/numa.h>
> @@ -256,6 +257,9 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
>   		 */
>   		pci_assign_unassigned_root_bus_resources(bus);
>   
> +		if (IS_ENABLED(CONFIG_SCREEN_INFO))
> +			screen_info_apply_fixups();
> +
>   		list_for_each_entry(child, &bus->children, node)
>   			pcie_bus_configure_settings(child);
>   	}

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Stefan Gaiser, Jochen Jaser, Abhinav Puri, (HRB 36809, AG Nürnberg)