Re: [PATCH v1 1/2] ACPI: CPPC: Fix up I/O port access in cpc_read()

[Huang Rui <ray.huang@amd.com>]

On Wed, Jan 12, 2022 at 07:26:32PM +0100, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> The code as currently implemented does not work on big endian systems,
> so fix it up.
> 
> Fixes: a2c8f92bea5f ("ACPI: CPPC: Implement support for SystemIO registers")
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> Suggested-by: Dan Carpenter <dan.carpenter@oracle.com>
> Link: https://lore.kernel.org/linux-acpi/20220111092928.GA24968@kili/
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Acked-by: Huang Rui <ray.huang@amd.com>

> ---
>  drivers/acpi/cppc_acpi.c |    4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> Index: linux-pm/drivers/acpi/cppc_acpi.c
> ===================================================================
> --- linux-pm.orig/drivers/acpi/cppc_acpi.c
> +++ linux-pm/drivers/acpi/cppc_acpi.c
> @@ -929,16 +929,18 @@ static int cpc_read(int cpu, struct cpc_
>  
>  	if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {
>  		u32 width = 8 << (reg->access_width - 1);
> +		u32 val_u32;
>  		acpi_status status;
>  
>  		status = acpi_os_read_port((acpi_io_address)reg->address,
> -					   (u32 *)val, width);
> +					   &val_u32, width);
>  		if (ACPI_FAILURE(status)) {
>  			pr_debug("Error: Failed to read SystemIO port %llx\n",
>  				 reg->address);
>  			return -EFAULT;
>  		}
>  
> +		*val = val_u32;
>  		return 0;
>  	} else if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM && pcc_ss_id >= 0)
>  		vaddr = GET_PCC_VADDR(reg->address, pcc_ss_id);
> 
> 
>