Re: [PATCH v1 1/1] x86/PCI: Disable e820 usage for the resource allocation

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 6/13/22 22:16, Andy Shevchenko wrote:
> The resource management improve for PCI on x86 broke booting of Intel MID
> platforms. It seems that the current code removes all available resources
> from the list and none of the PCI device may be initialized. Restore the
> old behaviour by force disabling the e820 usage for the resource allocation.
> 
> Fixes: 4c5e242d3e93 ("x86/PCI: Clip only host bridge windows for E820 regions")
> Depends-on: fa6dae5d8208 ("x86/PCI: Add kernel cmdline options to use/ignore E820 reserved regions")
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Andy, thank you for the patch. Commit 4c5e242d3e93 has also been causing
issues for other platforms, so I've submitted a revert of it here:

https://lore.kernel.org/linux-pci/20220612144325.85366-1-hdegoede@redhat.com/T/#u

can you please give the revert a try, and confirm that that fixes
the Intel MID platform issue too ?

Regards,

Hans



> ---
>  arch/x86/include/asm/pci_x86.h | 1 +
>  arch/x86/pci/acpi.c            | 2 +-
>  arch/x86/pci/intel_mid_pci.c   | 1 +
>  3 files changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h
> index f52a886d35cf..503f83fbc686 100644
> --- a/arch/x86/include/asm/pci_x86.h
> +++ b/arch/x86/include/asm/pci_x86.h
> @@ -126,6 +126,7 @@ extern const struct pci_raw_ops *raw_pci_ext_ops;
>  extern const struct pci_raw_ops pci_mmcfg;
>  extern const struct pci_raw_ops pci_direct_conf1;
>  extern bool port_cf9_safe;
> +extern bool pci_use_e820;
>  
>  /* arch_initcall level */
>  #ifdef CONFIG_PCI_DIRECT
> diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
> index a4f43054bc79..ac2f220d50fc 100644
> --- a/arch/x86/pci/acpi.c
> +++ b/arch/x86/pci/acpi.c
> @@ -20,7 +20,7 @@ struct pci_root_info {
>  #endif
>  };
>  
> -static bool pci_use_e820 = true;
> +bool pci_use_e820 = true;
>  static bool pci_use_crs = true;
>  static bool pci_ignore_seg;
>  
> diff --git a/arch/x86/pci/intel_mid_pci.c b/arch/x86/pci/intel_mid_pci.c
> index 8edd62206604..7869b86bff04 100644
> --- a/arch/x86/pci/intel_mid_pci.c
> +++ b/arch/x86/pci/intel_mid_pci.c
> @@ -313,6 +313,7 @@ int __init intel_mid_pci_init(void)
>  	pcibios_enable_irq = intel_mid_pci_irq_enable;
>  	pcibios_disable_irq = intel_mid_pci_irq_disable;
>  	pci_root_ops = intel_mid_pci_ops;
> +	pci_use_e820 = false;
>  	pci_soc_mode = 1;
>  	/* Continue with standard init */
>  	acpi_noirq_set();