[Letux-kernel] omap_hsmmc_init/omap_hsmmc_late_init

H. Nikolaus Schaller hns at goldelico.com
Sun Sep 10 18:41:29 CEST 2017


Hi,

> Am 10.09.2017 um 15:35 schrieb Grazvydas Ignotas <notasas at gmail.com>:
> 
> On Fri, Sep 8, 2017 at 7:50 PM, H. Nikolaus Schaller <hns at goldelico.com> wrote:
>>> Am 08.09.2017 um 18:00 schrieb Tony Lindgren <tony at atomide.com>:
>>> Hmm it might be possible to just init the MMC_QUIRK_NONSTD_SDIO
>>> in omap_hsmmc.c driver directly based on a custom compatible
>>> like "ti,omap4-hsmmc-wl1251".
>> 
>> Ah, that could be a simple addition. We do have others like
>> ti,non-removable or ti,needs-special-reset.
>> 
>>> But maybe there's some better
>>> solution that would be more future proof with the SDHCI driver
>>> work progressing nicely.
>>> 
>>> Anyways, getting rid of the platform_data for hsmmc sure
>>> would make things simpler.
>> 
>> To me it looks as if the key activity which makes it non-standard
>> is to call pandora_wl1251_init_card() after starting sdio.
>> 
>> And registering the wl1251 platform driver without DT (sdio subnode
>> support).
>> 
>> @notaz: what is your opinions?
> 
> The reason NONSTD_SDIO was needed is because wl1251 lacks standard
> SDIO registers that identify the chip and it's SDIO functions (only
> later TI chips have that). There was no way to pass that data through
> DT, so mmc3 was disabled in DT and started through platform_data with
> the data passed through using a quirk.

Ah, ok. This can probably not be replaced by standard-DT means.

So some ti,wl1251 quirk could just do that in the right moment.

I think the best place would be to make wl1251 a little DT compatible
and provide such identification properties. But that is a completely
different construction site.

> 
> I haven't followed the development for years now, so have no idea how
> to solve it best in current kernel.

> As there are no mainline users
> (nobody noticed the breakage for more than a year)

Mainly because other things are missing to make it useable in daily life
(no nubs, no sound). Therefore it is not well known that mainline support
almost exists and special advertising would not satisfy users. IMHO we
have to do the homework before we can attract more users.

> and it's broken
> without a known fix, it might make sense to just remove wl1251
> support.

Well, that seems to be a too easy solution :)

But it could raise the question to remove pandora support completely.
That is not something I want to see happen as it is contrary to the goals
of the Letux project (have all devices working and fixes upstreamed).

BR,
Nikolaus



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