Due to the known errata in E3800 SD card support, UHS-I might not work correctly. The suggestion is to make DDR50 support disabled by default in order to reduce the chance for a negative experience for the user/reduce support request volume. http://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/atom-e3800-family-spec-update.pdf " SD Card UHS-I Mode is Not Fully Supported Problem: The SD Card Specification rev 3.01 Addendum 1 specifies a relaxed NCRC (Number of clocks to Cyclic Redundancy Check) timing specification for UHS-I (DDR50) mode. Due to this erratum, the SD Host Controller is not fully compatible with this relaxed timing specification. Implication: Using UHS-I mode with SD devices that rely upon relaxed NCRC may cause SD host commands to fail to complete, resulting in device access failures. "
IS there a way we can disable this from the UEFI shell for testing? I've got an UHS-I card that's behaving oddly under Linux, and I'd like to try disabling this and seeing if it resolves the issue.
Yes, you can disable by setup page, please select "Device Manager -> System Setup -> South Cluster Configuration -> Lpss and Scc Configuration -> SD DDR50" to disable it.
ok that's working better, I'll try and get that mentioned on the wiki
The "SD DDR50" item on setup pages is disabled by default.