I've recently been testing memory card performance to identify the best performing brands/models. As expected, I found a huge difference in performance between brands. What I didn't expect to find, however, was a brand (ADATA) that doesn't seem to play well with the 2.6.36 kernel on OMAP3 hardware. I'm wondering if this failure might be exposing an issue in the OMAP mmc driver/hw setup. I tested both 4GB and 8GB versions of the ADATA Class 6 cards. I was not able to boot successfully from either card on both Overo and Beagle hardware (both 35xx and 37xx versions were tested). The error was the same in all cases: x-load, u-boot, and the kernel were all loaded successfully from SD, but the kernel was not able to mount the rootfs: Waiting for root device /dev/mmcblk0p2... mmc0: host does not support reading read-only switch. assuming write-enable. mmc0: new high speed SDHC card at address 0260 mmcblk0: mmc0:0260 SD 3.75 GiB mmcblk0: p1 p2 EXT3-fs: barriers not enabled kjournald starting. Commit interval 5 seconds EXT3-fs (mmcblk0p2): using internal journal EXT3-fs (mmcblk0p2): mounted filesystem with writeback data mode VFS: Mounted root (ext3 filesystem) on device 179:2. devtmpfs: mounted Freeing init memory: 168K INIT: version 2.86 booting Please wait: booting... Starting udev Remounting root file system... mmcblk0: error -110 sending read/write command, response 0x900, card status 0xe00 mmcblk0: error -110 transferring data, sector 3556505, nr 8, card status 0xc00 end_request: I/O error, dev mmcblk0, sector 3556512 Buffer I/O error on device mmcblk0p2, logical block 426490 lost page write due to I/O error on mmcblk0p2 mmcblk0: error -110 sending read/write command, response 0x900, card status 0xe00 mmcblk0: error -110 transferring data, sector 4076825, nr 8, card status 0xc00 end_request: I/O error, dev mmcblk0, sector 4076832 Buffer I/O error on device mmcblk0p2, logical block 491530 lost page write due to I/O error on mmcblk0p2 mmcblk0: error -110 sending read/write command, response 0x900, card status 0xe00 mmcblk0: error -110 transferring data, sector 4126233, nr 8, card status 0xc00 end_request: I/O error, dev mmcblk0, sector 4126234 Buffer I/O error on device mmcblk0p2, logical block 497706 lost page write due to I/O error on mmcblk0p2 And so on, with many more mmc errors. If I reset and try again, things go wrong even sooner: Waiting for root device /dev/mmcblk0p2... mmc0: host does not support reading read-only switch. assuming write-enable. mmc0: new high speed SDHC card at address 0260 mmcblk0: mmc0:0260 SD 3.75 GiB mmcblk0: p1 p2 EXT3-fs: barriers not enabled mmcblk0: error -110 sending read/write command, response 0x900, card status 0xe00 mmcblk0: error -110 transferring data, sector 147545, nr 8, card status 0xc00 end_request: I/O error, dev mmcblk0, sector 147552 Buffer I/O error on device mmcblk0p2, logical block 370 lost page write due to I/O error on mmcblk0p2 The ADATA cards seem to work with no issues on my desktop system. Has anyone else run into this issue? Any theories on where to start looking? FWIW, there is this thread on the beagleboard list discussing issues with mmc writes: http://groups.google.com/group/beagleboard/browse_thread/thread/0083724ff7e54c58/f55578bb1c1379db#f55578bb1c1379db In this thread Gerald Coley speculates that the driver may be setting the mmc1 voltage to 3.0V rather than 3.15V. Regards, Steve PS: For those who might be interested in the microSD card performance tests: http://www.sakoman.com/OMAP/microsd-card-perfomance-test-results.html -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
