On Wed, Aug 06, 2014 at 04:28:26PM -0700, Christopher Heiny wrote: > [I sent this last Thursday, but it never showed up on the input > list. I'm assuming nobody else saw it.] > > > On 07/31/2014 02:58 PM, Dmitry Torokhov wrote: > >On Thu, Jul 31, 2014 at 02:43:47PM -0700, Christopher Heiny wrote: > >>On 07/31/2014 02:19 PM, Dmitry Torokhov wrote: > >>>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. > >> > >>Sorry! My answer wasn't very clear on that part, was it? > >> > >>The manual binding gets the reflash (if required) done very early in > >>the boot/probe process. This eliminates the need to set up the > >>whole sensor + functions structure, tear it down in order to > >>reflash, and then build it all back up again. It is felt that the > >>time savings is significant, especially on highly featured products. > > > >I am sorry but I have hard time accepting this argument. How often do > >you reflash devices during normal operation and how long does it take to > >initialize the device compared to getting entire userspace up and > >running to be able to actually supply or serve flash data (even without > >using usermode helper to flash you need filesystem with the firmware to > >be mounted)? > > That was my argument exactly, but that was the direction we were > pushed. I'd much rather implement it as we discussed offline > earlier this week. If you were to say: "I'm sorry, but this simply > can't be merged as it stands." you wouldn't get any argument from me > on technical grounds. There might be people who will argue about the > additional calendar time it would take to restructure it, though. OK, then I will just say this: "I'm sorry, but this simply can't be merged as it stands." Now, I am talking about mainline here, I am fairly certain we can resolve scheduling issues between what you currently have and what is needed in the end. Thanks. -- Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
