Re: a problem about the function of acpi_ec_read_data

[Alexey Starikovskiy <astarikovskiy@suse.de>]

Hi Zhao,
Good catch, it is probably debug patch gone bad. it is definitely needs to read "return x;"
Please submit patch, I ACK it.
Thanks,
Alex.


Zhao Yakui wrote:
> Hi, Alexey
>     There is a question about the function of acpi_ec_read_data.
>  
>     When the data is ready for OS, OS will check the OBF flag of EC status and then call the following
> function to read the data returned by EC controller.
> 
> static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
> {
>         u8 x = inb(ec->data_addr);
>         pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
>         return inb(ec->data_addr);
> }
> 
>     Why is the EC data I/O address accessed twice to get the data returned by EC controller?
>     Does there exist some specific reason about it?
>  
> Thanks for the comments.
> 
> Best regards.
>    Yakui
>