Re: [PATCH v2 05/06] input synaptics-rmi4: Add firmware update support

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Thu, Jul 31, 2014 at 02:00:14PM -0700, Christopher Heiny wrote:
> On 07/31/2014 10:53 AM, Dmitry Torokhov wrote:
> >Hi Christopher,
> >
> >On Wed, Mar 12, 2014 at 06:53:56PM -0700, Christopher Heiny wrote:
> >>Add support for updating firmware on RMI4 devices with V5 bootloader.
> >
> >I am wondering why F34 is not following the staindard RMI function
> >implementation. By that I mean that it does not declare itself as struct
> >rmi_function_handler and does not rely on RMI core to bind itself to the device
> >if device supports it.
> 
> Hi Dmitry,
> 
> We originally had an F34 implementation that followed the RMI4
> function standard and exposed most of the basic F34 operations via
> sysfs. However, we got feedback (both on LKML and offline) (a)
> recommending to use request_firmware, and (b) improve reflash times
> while (c) reducing impact on boot time, and (d) "get rid of all that
> sysfs crap" (paraphrased, but close to it).
> 
> So after looking at how some other drivers use request_firmware, we
> came up with the current approach.  Switching to request_firmware
> definitely sped up the reflash times!  Including a check to see if
> firmware update is required before setting up the RMI4
> sensor/function structures also significantly reduced boot times.

I am not suggesting you stop using request-firmware or introduce
bazillion of new sysfs attributes. I just wondered why you have manual
"binding" of F34 functionality instead of standrad RMI4 function
binding, liek you do for F01, F11 and so forth.

Thanks.

-- 
Dmitry