Re: [PATCH 1/3] mfd: cros_ec: Add Chrome OS EC userspace device interface

[Javier Martinez Canillas <javier.martinez@collabora.co.uk>]

Hello Alan,

Thanks a lot for your feedback.

On 11/18/2014 06:00 PM, One Thousand Gnomes wrote:
>> +#ifdef CONFIG_COMPAT
>> +struct compat_cros_ec_command {
>> +	uint32_t version;
>> +	uint32_t command;
>> +	compat_uptr_t outdata;
>> +	uint32_t outsize;
>> +	compat_uptr_t indata;
>> +	uint32_t insize;
>> +	uint32_t result;
>> +};
>> +
>> +struct compat_cros_ec_readmem {
>> +	uint32_t offset;
>> +	uint32_t bytes;
>> +	compat_uptr_t buffer;
>> +};
>> 
> 
> This is a new API - arrange them to be 64bit safe and properly padded,
> there is no excuse for needing compat crap except for legacy interfaces
> you can't fix.
> 

Is true that this is a new API for mainline but there is a lot of ChromeOS
installations that depends on this API which means that just replacing the
kernel with a mainline one there, will break existing user-space programs.

But I understand that since those binaries were using a non-ustream kernel
it is expected that the kernel API could be changed.

I think it would be great to keep existing binaries working but if changing
the API is required, then I can certainly do that when doing a re-spin.

Best regards,
Javier