For my part, I've just finished testing my smallish set of cards, covering class 4,6,10 and one with UHS-1. Several of which have had problems with various combinations of patches. They now all work. Some variation in performance (the class10/uhs-1 is the slowest!), but all show marked improvement in the range of 3x to 4x. None of the mmc0: timeout.... style errors that were present during boot even for working cards previously.
Awesome! That is really great news. I have a good selection of older cards (even some *ancient* MMC cards), but not many newer cards, and no UHS-1 card. But all of them work. I think we can pretty safely assume the card compatibility and performance issues are gone for good now.
Seems odd that the UHS-1 card performs badly. What does "cat /sys/devices/platform/bcm2708_sdhci.0/status" report for it?
WOW - even on a class 4 card? If that is the case, is there even any point of having anything faster?
The class indicates write
performance. Generally, reads are pretty fast even among bad and slow cards. Higher classes indicates better write speed*.
(*Caveat: the class refers to sequential write performance. However, for an OS installation that has many small files, random write performance is more important, and most SD cards suck really badly at this, independent of class)
Larry_Adlard wrote:Kernel 20120611 is a step too far for my Class 4 card. All I get is error 110 and 84. So I'm reverting to 20120610.
The Class 10 card only gets error 110, It doesn't report error 84.
Have you reduced the eMMC clock to 50 MHz with "init_emmc_clock=50000000" in config.txt? This is absolutely