Hi, I'm aware that the DDR50 mode is not fully supported. The clock appears to be unstable when SDCARD host running with DDR50 mode. We have a workaround that introduce a new quirk to force host with broken DDR50 mode to run with SDR25 mode. As we think that this workaround might not be suitable to be upstream to mainline kernel, this workaround will be implemented in our valleyisland-io feature branch in future. We are now working on backporting our features from mainline kernel to LTSI/LTS kernel. And eventually all those workaround that do not fit upstream criteria will be implemented temporary in feature branch.
I'm not sure whether I can provide you the workaround patch here. I will work with our driver developers in order to help you in this. You may file a bug in bugzilla so that we got track on your enquiry. Thanks a lot. Rebecca From: IGI/Falk Bauer [mailto:f.ba...@igi-systems.com] Sent: 12 May, 2014 5:37 PM To: Chang, Rebecca Swee Fun Cc: meta-intel@yoctoproject.org Subject: Valleyisland SDIO support Hello Rebecca, thanks for your recently work with the Baytrail board. I can confirm that the image in dora branch is working with full OpenGL support. Here is another question relating to the SDIO controller embedded into the atom processor. In the intel specifiction update from january 2014 (http://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/atom-Z36xxx-Z37xxx-spec-update.pdf) there is an entry named "VLT55 SD Card UHS - I Mode is Not Fully Supported". We have issues here with sd cards from sandisk which are running into error messages like ********** May 7 16:27:53 valleyisland-32 user.debug kernel: [ 125.254962] sdhci-pci 0000:00:12.0: setting latency timer to 64 May 7 16:27:55 valleyisland-32 user.info kernel: [ 127.510449] mmc1: new ultra high speed DDR50 SDHC card at address e624 May 7 16:27:55 valleyisland-32 user.info kernel: [ 127.511010] mmcblk0: mmc1:e624 SD08G 7.40 GiB May 7 16:27:55 valleyisland-32 user.info kernel: [ 127.520193] mmcblk0: p1 May 7 16:27:55 valleyisland-32 user.err kernel: [ 127.526524] mmcblk0: error -84 transferring data, sector 15523712, nr 8, cmd response 0x900, card status 0xb00 May 7 16:27:55 valleyisland-32 user.warn kernel: [ 127.526534] mmcblk0: retrying using single block read May 7 16:27:55 valleyisland-32 user.err kernel: [ 127.529319] mmcblk0: error -84 transferring data, sector 15523712, nr 8, cmd response 0x900, card status 0x0 May 7 16:27:55 valleyisland-32 user.warn kernel: [ 127.529329] blk_update_request: 773 callbacks suppressed May 7 16:27:55 valleyisland-32 user.err kernel: [ 127.529335] end_request: I/O error, dev mmcblk0, sector 15523712 May 7 16:27:55 valleyisland-32 user.err kernel: [ 127.531980] mmcblk0: error -84 transferring data, sector 15523713, nr 7, cmd response 0x900, card status 0x0 May 7 16:27:55 valleyisland-32 user.err kernel: [ 127.531990] end_request: I/O error, dev mmcblk0, sector 15523713 ********** These messages appears in the kernel log buffer after inserting an sd card SanDisk Extreme 30 MB/s, class 10 UHS 1 8GB (vendor name in sysfs is SU08G). Further investigations reveals that the error reproduce is related to the kind of sd card, filesystem on the partition aso. I think that the errata vlt55 leads to the messages in the log. Have you experienced some similar issues with the Z3000 atom series? Or is there some plans or possibilities to disable the UHS feature for the SDIO device embedded in the atom cpu? I know that in the specification update there is currently the "no fix" entry. But maybe there is some "quick-and-dirty" fix like a "SDHCI_QUIRK2_BROKEN_UHS" define or so in the sdhci module in the kernel. If you wish i can also fill a bug in bugzilla. Falk ________________________________ IGI - Ingenieur-Gesellschaft fuer Interfaces mbH Dipl.-Ing. Falk Bauer Applications Engineer Langenauer Str. 46 57223 Kreuztal, Germany Tel.: +49 2732 5525 0 Fax: +49 2732 5525 25 E-mail: f.ba...@igi-systems.com<mailto:f.ba...@igi-systems.com> Internet: www.igi-systems.com<http://www.igi.eu/news.html> Follow us: [IGI News Feed]<http://www.igi.eu/IGI_News.xml> [IGI at YouTube] <http://www.youtube.com/IGISystems> [LinkedIn] <http://www.linkedin.com/company/follow/submit?id=2662318&fl=start&ft=pageKey%3Dbiz-overview-internal%3Bmodule%3Dbutton&csrfToken=ajax%3A8766554907507224198&goback=%2Enmp_*1_*1_*1_*1_*1_*1_*1_*1_*1_*1_*1%2Ebzo_*1_*1_*1_*1_*1_*1_*1_igi*5systems&trk=co_fol-start-3> [IGI Logo]<http://www.igi.eu/news.html> ________________________________ Meet us: Geospatial World Forum in Geneve (5-9 May)<http://www.igi.eu/event-reader/events/geospatial-world-forum-in-geneve-switzerland.html> * Geo Business in London (28+29 May)<http://www.igi.eu/event-reader/events/geo-business-2014-in-london-uk.html> ________________________________
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