+ Bjorn, Sarthak, Veerabhadrarao On Fri, 22 May 2020 at 17:51, Iskren Chernev <iskren.chernev@xxxxxxxxx> wrote: > > > Hello, > > I'm trying to add SD Card support to a smartphone (Samsung Galaxy S5). After > configuring the sdhci-msm driver through DT, it all seems to work fine except > the case when the phone boots with the SD card inserted. If the card is > re-inserted, or the driver is polling, or the probe code is forcefully executed > a second time the card is properly detected. > > I logged the SD interrupts, commands and responses, and it looks like the > hardware is returning Command Index Error and/or Command End Bit Error via the > Error Interrupt Status Register, which gets converted to -EILSEQ error. On > a second attempt (due to re-insertion, polling or re-execution) these errors > are missing, and the card behaves correctly. > > On the downstream kernel, these errors resulting in EILSEQ do not appear, so it > might be related to setup. Also I see that sdhci-msm driver has hardcoded > a SDHCI_QUIRK_BROKEN_CARD_DETECTION quirk, which might imply that polling > should be used (instead Card Detection GPIO), in which case this issue won't > manifest itself. But polling wastes power, and the Card Detect pin works well, > at least for this device, so I feel it can be made better. > > Any suggestions on how to track this down are appreciated! I think the device is intended to be used with GPIO card detection. Polling mode shouldn't be needed if there is GPIO. Anyway, to me it sounds like the HW/controller isn't properly initialized during ->probe(), but I can't help you much more than that. I have looped in some of the recent active sdhci-msm developers to see if they have some ideas that we can try. Kind regards Uffe
