[Letux-kernel] Pandora WiFi / wl1251 driver

H. Nikolaus Schaller hns at goldelico.com
Tue Oct 1 11:50:58 CEST 2019


> Am 26.09.2019 um 14:59 schrieb H. Nikolaus Schaller <hns at goldelico.com>:
> 
> 
>> Am 25.09.2019 um 18:31 schrieb H. Nikolaus Schaller <hns at goldelico.com>:
>> 
>> Now let's check if a revert fixes the issue for 4.7-rc1 or even 4.7.
>> 
>> But there may be follow-up fixes for this patch to consider.
>> 
>> Then we have to find out what the real problem is. Maybe some component
>> doesn't support deferred probing. Or the DMA setup for omap3 mmc3
>> has a bug that nobody else did notice (the mmc3 interface is rarely
>> used by boards - as far as I can see only omap3-zoom3 and pandora).
> 
> Ok, the key reason is that the patch introduced in 4.7 assumes that
> mmc3 is instantiated through device tree because it now searches the
> dma channel through device tree.
> 
> But the pdata-quirk for OpenPandora doesn't have a device tree entry.
> 
> So we have to get rid of the pdata-quirk code, let DT create the
> mmc3 device and driver and have the w1251 as a child node.
> 
> This works!
> 
> http://git.goldelico.com/?p=letux-kernel.git;a=shortlog;h=refs/heads/letux-base-4.7/pandora-wifi
> 
> Next, I have to check if we can forward-port this to 4.14, 4.19
> and to the tip of the letux development.

Yes, it can be forward-ported and is in the queue.

But WiFi is now breaking around v4.11. It was difficult to debug
because there was another bug on the OpenPandora device tree that
did manifest itself for the first time in letux-4.11-rc1 and was fixed
in letux-4.12-rc5. After fixing that as well, I did now run a bisect
between 4.10-rc1 (where WiFi is working) and 4.11-rc1 (where WiFi is broken),
but the result is not clear:

# first bad commit: [37c85961c3f87f2141c84e53df31e59db072fd2e] Merge tag 'tty-4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

There are also other bugs arriving around that commit range:
* there are messages about bad locking when doing ifdown/up usb0
* usb0 isn't working after reboot if cable is still plugged in
* the right SD slot seems to stop working as well

So it seems as if we got several still unfixed bugs from upstream back then.

Currently, upgrading the LetuxOS Kernel tree to v5.4-rc1 has higher priority.

BR,
Nikolaus



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