We are developing a SDMMC driver for RISC OS. We have similar issues , but not exactly the same. Some sd cards works and some don't. The symptoms can be anything from not detected at all to fail in writing (mounts successfully).
We think we got the clock setup right , even if it has been a long journey to get there.
One thing that worries me is that CMD6 returns same data when querying cards of different speeds. So our driver always thinks that 25Mhz is the max the card supports.
I wonder , what is the CMD6 output in linux and is it used at all in linux? Since the output is always the same , the speed setting in card also might fail, no way to find out. The read operation of CMD6 is successful , driver wise.
That's all I got at the moment. We are two developers working with it and it has been very confused. I thought really long that my PbP was faulty.
We think we got the clock setup right , even if it has been a long journey to get there.
One thing that worries me is that CMD6 returns same data when querying cards of different speeds. So our driver always thinks that 25Mhz is the max the card supports.
I wonder , what is the CMD6 output in linux and is it used at all in linux? Since the output is always the same , the speed setting in card also might fail, no way to find out. The read operation of CMD6 is successful , driver wise.
That's all I got at the moment. We are two developers working with it and it has been very confused. I thought really long that my PbP was faulty.