Hi Claudiu, but one thing I can ask already: > Investigating it on RZ/G3S lead to the conclusion that every time the issue > is reproduced all the probed TAPs are OK. According to datasheet, when this > happens the change point of data need to be considered for tuning. Yes, "considered" means here it should be *avoided*. > Previous code considered the change point of data happens when the content > of the SMPCMP register is zero. According to RZ/V2M hardware manual, When SMPCMP is zero, there is *no* change point. Which is good. > chapter "Change Point of the Input Data" (as this is the most clear > description that I've found about change point of the input data and all > RZ hardware manual are similar on this chapter), I also have a chapter named like this. If you check the diagram, change point is between TAP2 and 3, so the suggested TAP to use is 6 or 7. As far away as possible from the change point. > at the time of tuning, > data is captured by the previous and next TAPs and the result is stored in > the SMPCMP register (previous TAP in bits 22..16, next TAP in bits 7..0). > If there is a mismatch b/w the previous and the next TAPs, it indicates > that there is a change point of the input data. This is correct. > To comply with this, the code checks if this mismatch is present and > updates the priv->smpcmp mask. That means you select the "change point" instead of avoiding it? > This change has been checked on the devices with the following DTSes by > doing 50 consecutive reboots and checking for the tuning failure message: Okay, you might not have a failure message, but you might have selected the worst TAP. Or? > + if (cmpngu_data != cmpngd_data) > + set_bit(i, priv->smpcmp); Really looks like you select the change point instead of avoiding it. However, with some SD cards, I also see the EIO error you see. So, there might be room to improve TAP selection when all TAPs are good. I need to check if this is really is the same case for the SD cards in question. Happy hacking, Wolfram
Attachment:
signature.asc
Description: PGP signature
