Re: [RFT] mmc: tmio: reset device on timeout, too

[Wolfram Sang <wsa+renesas@sang-engineering.com>]

[-- Attachment #1: Type: text/plain, Size: 1465 bytes --]

Hi Ulf,

> > Hmm, there are some wireless drivers using it as well. I am confused, is
> > this considered "upper layer"?
> >
> > drivers/net/wireless/ath/ath10k/sdio.c: ret = mmc_hw_reset(ar_sdio->func->card->host);
> > drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c:        mmc_hw_reset(sdiodev->func1->card->host);
> > drivers/net/wireless/marvell/mwifiex/sdio.c:    ret = mmc_hw_reset(func->card->host);
> > drivers/net/wireless/ti/wlcore/sdio.c:  mmc_hw_reset(card->host);
> 
> Correct, these are "upper layers". The same applies for the mmc block
> device driver.
> 
> In this way there is a guarantee that the struct mmc_card is still present.

Ah, now I get it. "upper layers" as in consumers. And because consumers
sit on a card, this guarantees that mmc_card is still there. Correct?

> That would be great. I appreciate all kinds of improvements on the doc parts.

You are welcome!

> Perhaps a better option is to return a specific error code for the
> last request, that makes the core run mmc_hw_reset(). Or potentially,
> add a host cap and let the core treat some error code, specifically
> for hosts like tmio.

A specific errno could work. I don't see the advantage of a CAP (besides
it is rather a quirk than a cap). We could also have
'mmc_controller_card_reset()' or something which ensures mmc_card is
present and let that controllers call when they see fit. Or?

Thanks for your help,

   Wolfram


[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]