On Wed, Jun 30, 2021 at 5:28 PM Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote: > > /* Handle busy detection on DAT0 if the variant supports it. */ > > if (busy_resp && host->variant->busy_detect) > > if (!host->ops->busy_complete(host, status, err_msk)) > > return; > > > > These seemed to be especially problematic to me. > > Yes, exactly. The IRQ based busy detection code gets disabled with my > debug patch. > > It looks like there are some race conditions in the HW busy detection > path for mmci, which gets triggered by this eMMC card. (...) > Although, it's more optimal to receive an IRQ when busy on DAT0 is > de-asserted, rather than polling with ->card_busy(). Hence we also > have MMC_CAP_WAIT_WHILE_BUSY. Hmmmmm it kind of assumes that DAT0 will be de-asserted *before* we get a command response, never after. I think that is what the card is doing. If that is out-of-spec then we need to have a quirk like this but if it is legal behaviour, we rather need to fix the mmci driver. Yours, Linus Walleij
