[PATCH 1/2] mmc: core: use card pointer as the first parameter of execute_tuning()

Russell King - ARM Linux linux at arm.linux.org.uk
Mon Jan 26 09:48:45 PST 2015


On Mon, Jan 26, 2015 at 09:45:07AM -0800, Doug Anderson wrote:
> Ulf,
> 
> On Mon, Jan 26, 2015 at 7:15 AM, Ulf Hansson <ulf.hansson at linaro.org> wrote:
> > On 26 January 2015 at 12:19, Addy Ke <addy.ke at rock-chips.com> wrote:
> >> We need to take the card pointer in execute_tuning() for mmc_send_status(),
> >
> > mmc_send_status() is an mmc core function, not intended for host's to call.
> >
> >> but mmc->card is NULL in tuning state. So we need change the first parameter
> >> of execute_tuning() to card pointer(struct mmc_card * card).
> >
> > So, why do we need this?
> 
> I asked Addy to post upstream against mmc_send_tuning(), but I guess
> he didn't (he posted against Alex's NAKed patch instead).
> 
> ...when I talked to him about it, Addy was asserting that when tuning
> fails it is important (at least on dw_mmc on rk3288) that we wait for
> the card to stop being busy and that the way to detect was using
> mmc_send_status().
> 
> That would mean that against upstream you'd need to change
> mmc_send_tuning() to take in the card as well (or move the "host->card
> = card" assignment to before UHS init, which seems less desirable?)
> 
> What do you think about that?  Is there a better solution?

That sounds like a generic thing though - in which case, what do the
specs have to say on this, and does the code implement what it says?

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