Re: [PATCH 1/3] brcmfmac: re-enable command decode in sdio_aos for BRCM 4354

From: Arend Van Spriel
Date: Mon May 20 2019 - 04:12:06 EST




On 5/18/2019 12:54 AM, Douglas Anderson wrote:
In commit 29f6589140a1 ("brcmfmac: disable command decode in
sdio_aos") we disabled something called "command decode in sdio_aos"
for a whole bunch of Broadcom SDIO WiFi parts.

After that patch landed I find that my kernel log on
rk3288-veyron-minnie and rk3288-veyron-speedy is filled with:
brcmfmac: brcmf_sdio_bus_sleep: error while changing bus sleep state -110

This seems to happen every time the Broadcom WiFi transitions out of
sleep mode. Reverting the part of the commit that affects the WiFi on
my boards fixes the problem for me, so that's what this patch does.

This sounds very similar to the issue we had during integration of wifi on rk3288 chromebooks years ago.

Note that, in general, the justification in the original commit seemed
a little weak. It looked like someone was testing on a SD card
controller that would sometimes die if there were CRC errors on the
bus. This used to happen back in early days of dw_mmc (the controller
on my boards), but we fixed it. Disabling a feature on all boards
just because one SD card controller is broken seems bad. ...so
instead of just this patch possibly the right thing to do is to fully
revert the original commit.

I am leaning towards a full revert, but let's wait for more background info.

Regards,
Arend