Hi Nikolaus, On Thursday 28 October 2021 09:08:50 CEST H. Nikolaus Schaller wrote: > > Am 27.10.2021 um 23:31 schrieb Ulf Hansson <ulf.hansson@xxxxxxxxxx>: > > On Wed, 27 Oct 2021 at 19:01, H. Nikolaus Schaller <hns@xxxxxxxxxxxxx> wrote: > >>> Am 26.10.2021 um 20:08 schrieb H. Nikolaus Schaller <hns@xxxxxxxxxxxxx>: > >>>> As a matter of fact, the similar problem that you are looking to > >>>> address (applying card quirks based on DT compatibility strings), is > >>>> partly being taken care of in another series [1], being discussed > >>>> right now. I think the solution for the ti,wl1251 should be based upon > >>>> that too. Please have a look and see if you can play with that!? > >>> > >>> That is interesting. > >>> Yes, maybe it can be the basis. At least for finding the chip and driver. > >> > >> I have done a first experiment. > >> > >> It seems as if the series [1] does the opposite of what we need... It just > >> skips entries in struct mmc_fixup if the DT does *not* match. > > > > Ohh, I didn't look that close. In that case the code isn't doing what > > it *should*. The point is really to match on the compatible string and > > then add quirks if that is found. > > That is what I had expected. Note I have not tested this code. My primary goal was to submit the idea. I think I will be able to send a true PR next week. > > Let me have a closer look - and for sure, I am willing to help if needed. I confirm it does not have the expected behavior. !mmc_fixup_of_compatible_match() should be mmc_fixup_of_compatible_match(), sorry. [...] > >> What I don't get from the code is how cis.vendor or cis.device can be > >> initialized from device tree for a specific device. As far as I see it can > >> only be checked for and some quirks can be set from a table if vendor and > >> device read from the CIS registers do match. > > > > Yes. I thought that should be possible, but maybe it is not? > > It seems to be a hen or egg issue here. MMC_QUIRK_NONSTD_SDIO should be set > before we can match by vendor and device or compatible. But it can't be set > late. I think you can add a new fixup table that could be applied earlier (as you do in your suggestion below). > >> Instead, we want to match DT and define some values for an otherwise unknown > >> device (i.e. we can't match by vendor or other methods) to help to initialize > >> the interface. So in mmc_fixup_device it is too late and we need something > >> running earlier, based purely on device tree information... > > > > Okay, I will have a closer look. Maybe we need to extend the card > > quirks interface a bit to make it suitable for this case too. > > Combining your suggestions we could do roughly: > > in mmc_sdio_init_card(): > > if (host->ops->init_card) > host->ops->init_card(host, card); > else > mmc_fixup_device(host, sdio_prepare_fixups_methods); I think I mostly agree, but why you don't call mmc_fixup_device() if init_card is defined? (BTW, mmc_fixup_device() takes a card as first parameter) > Next we need a location for the sdio_prepare_fixups_methods table and functions. > > For "ti,wl1251" we would then provide the entry in the table and a function doing > the setup. But where should these be defined? Likely not in a header file like > quirks.h? But there is no quirks.c. I think you can place your function in drivers/mmc/core/card.h. There are already add_quirk(), add_limit_rate_quirk(), add_quirk_mmc(), etc... -- Jérôme Pouiller
