> Sorry for the slow reply. > I would expect if there was a general problem with DDR50 SD cards, > it would have come to light before now. > Does the card work with any other host controllers with linux? > If it is specific to a particular kind of card, a card quirk > could be added, say MMC_QUIRK_BROKEN_DDR50_TUNING No worries. I have not tested this with other host controllers but can try to get something set up. This issue has only appeared on one particular SD card model for us so I would not be surprised if the I/O errors we see on subsequent tune requests are specific to this card. I can put together a solution using the card quirk you suggested if you think that is the best way forward. My fix is currently spread across two commits, one to return the error code thrown by the tune request timing out, which prevents the card from retuning, and this one that prevents the initial card tuning if it has already failed. Should both parts be controlled by the new card quirk? Regards, Erick
