On Sat, 14 Sept 2024 at 13:52, Heiko Stübner <heiko@xxxxxxxxx> wrote: > > Am Donnerstag, 12. September 2024, 09:26:14 CEST schrieb Kever Yang: > > In order to make the SD card hotplug working we need the card detect > > function logic inside the controller always working. The runtime PM will > > gate the clock and the power domain, which stops controller working when > > no data transfer happen. > > > > So lets skip enable runtime PM when the card needs to detected by the > > controller and the card is removable. > > > > Signed-off-by: Kever Yang <kever.yang@xxxxxxxxxxxxxx> > > So for the change itself this looks good, i.e. it fixes an issue for baords relying > on the on-chip-card-detect. > > > But for boards doing that, the controller will be running _all the time_ > even if there is never any card inserted. > > So relying on the on-soc card-detect will effectively increase the power- > consumption of the board - even it it'll never use any sd-card? Good point! A better option is to use a polling based mechanism - and we have MMC_CAP_NEEDS_POLL for exactly that. Moreover, on DT based platforms one can even use the "broken-cd" property to indicate this. [...] Kind regards Uffe
