Supported microSD cards/SD-C02G
Kingston SD-C02G works fine at good GSM coverage with the following kernel parameters here (GTA02 with GPS capacitor fix on uSD slot):
Lower drive strength or or higher clock speed cause unreliable behavior if the GSM modem is activated (either directly after entering the PIN, when making a call, or using GPRS - more often while having bad GSM reception and using GPRS):
Sep 15 14:15:20 debian-gta02 kernel: mmcblk0: error -84 sending read/write command
Sep 15 14:15:20 debian-gta02 kernel: glamo-mci glamo-mci.0: Error after cmd: 0x4304
Drive strength of 0 at glamo_mci.sd_max_clk=10000000 is pretty reliable at normal operation (at good GSM reception), but still fails sometimes when GPRS is activated. Drive strength of 2 still fails repeatably when using GSM in less populated area or when accessing SD card directly after entering PIN.
(last verified using 2008.8 and newer daily kernel versions)
- SD idle clock = on does not prevent the errors
- Errors occur almost every time when loading things from SD card while entering PIN, even at drive strength of 3 and clock speed of 2.5 Mhz
- Verify the card is indeed the only one affected (ruling out FreeRunner HW problems is hard, only got one)
- Try to reproduce that GSM affects SD data lines themselves, not only the card
- Verify that screen sometimes filling with random data when card fails is related to failing card, and not to failing glamo which in turn results in card errors.
- Find out if it also happens in areas without GSM buzz.