Re: [PATCH v2 04/11] mmc: host: omap_hsmmc: add code for special init of wl1251 to get rid of pandora_wl1251_init_card

Hi Ulf,

Am 30.10.2019 um 16:51 schrieb Ulf Hansson [off-list ref]:

quoted

+
+               np = of_get_compatible_child(np, "ti,wl1251");
+               if (np) {
+                       /*
+                        * We have TI wl1251 attached to MMC3. Pass this information to
+                        * SDIO core because it can't be probed by normal methods.
+                        */
+
+                       dev_info(host->dev, "found wl1251\n");
+                       card->quirks |= MMC_QUIRK_NONSTD_SDIO;
+                       card->cccr.wide_bus = 1;
+                       card->cis.vendor = 0x104c;
+                       card->cis.device = 0x9066;
+                       card->cis.blksize = 512;
+                       card->cis.max_dtr = 24000000;
+                       card->ocr = 0x80;

These things should really be figured out by the mmc core during SDIO
card initialization itself, not via the host ops ->init_card()
callback. That is just poor hack, which in the long run should go
away.

Yes, I agree.

But I am just the poor guy who is trying to fix really broken code with
as low effort as possible.

I don't even have a significant clue what this code is exactly doing and what
the magic values mean. They were setup by pandora_wl1251_init_card() in the
same way so that I have just moved the code here and make it called in (almost)
the same situation.

Moreover, I think we should add a subnode to the host node in the DT,
to describe the embedded SDIO card, rather than parsing the subnode
for the SDIO func - as that seems wrong to me.

You mean a second subnode?

The wl1251 is the child node of the mmc node and describes the SDIO card.
We just check if it is a wl1251 or e.g. wl1837 or something else or even
no child.

To add a subnode for the SDIO card, we already have a binding that I
think we should extend. Please have a look at
Documentation/devicetree/bindings/mmc/mmc-card.txt.

If you want an example of how to implement this for your case, do a
git grep "broken-hpi" in the driver/mmc/core/, I think it will tell
you more of what I have in mind.

So while I agree that it should be improved in the long run, we should
IMHO fix the hack first (broken since v4.9!), even if it remains a hack
for now. Improving this part seems to be quite independent and focussed
on the mmc subsystem, while the other patches involve other subsystems.

Maybe should we make a REVISIT note in the code? Or add something to
the commit message about the idea how it should be done right?

quoted

+                       of_node_put(np);
+               }
+       }
}

static void omap_hsmmc_enable_sdio_irq(struct mmc_host *mmc, int enable)
--
2.19.1

Kind regards
Uffe

BR and thanks,
Nikolaus