Hi Heiko,
? 2016/4/2 7:52, Heiko Stuebner ??:
> Hi Shawn,
>
> it looks like commit ea9849113343 ("spi: rockchip: check return value of
> dmaengine_prep_slave_sg") negatively affects the cros_ec spi backend.
>
> During boot on the most recent mainline kernel I get:
>
> [ 1.025480] cros-ec-spi spi0.0: Chrome EC device registered
> [ 1.641636] input: cros_ec as /devices/platform/ff110000.spi/spi_master/spi0/spi0.0/ff110000.spi:ec at 0:keyboard-controller/input/input0
> [ 2.340214] cros-ec-spi spi0.0: EC failed to respond in time
> [ 2.357735] cros-ec-spi spi0.0: packet too long (249 bytes, expected 4)
> [ 2.470353] cros-ec-spi spi0.0: EC failed to respond in time
> [ 2.508495] cros-ec-spi spi0.0: packet too long (249 bytes, expected 4)
> [ 2.620176] cros-ec-spi spi0.0: EC failed to respond in time
> [ 2.637345] cros-ec-spi spi0.0: packet too long (249 bytes, expected 4)
> [ 2.750245] cros-ec-spi spi0.0: EC failed to respond in time
> [ 2.767519] cros-ec-spi spi0.0: packet too long (249 bytes, expected 4)
>
> The cros-ec works ok after boot without further errors [aka keyboard
> and everything working correctly] and I haven't been able to figure out
> what goes wrong, but was able to bisect the issue down to the commit
> mentioned above.
>
Which Soc I can reproduce it?
I'm not able to find out how this commit to break the cros-ec. So I
prone to think this commit just expose some issues rather than
introducing negatively affects. I guess, before this commit, cros-ec
always get successful transfer, but the reality is that the tranfer
does failed in the early booting stage but spi-rockchip doesn't log out
anything. If that is the case, that means spi-rockchip fails to prepare
sg for some unknown reasons?
> Reverting the patch silences the cros-ec again. I'll try to look into it
> further, but maybe you also have an idea what might go wrong.
>
>
> Heiko
>
> _______________________________________________
> Linux-rockchip mailing list
> Linux-rockchip at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-rockchip
>
--
Best Regards
Shawn Lin
