Hi Folks,
I am running Linux kernel 3.8.13-00794-g59be459-dirty with buildroot-fs on Beagle-Bone-Black.
I have installed mmc-utils package, and executed the following command:
# mmc extcsd read /dev/mmcblk0
[ 34.863647] mmc_claim_host exectued
[ 34.867380] calling mmc_wait_for_req
[ 34.871147] ** mmc0: starting CMD8 arg 00000000 flags 000000b5
[ 34.877754] omap_hsmmc mmc.5: mmc_blk_ioctl_cmd: cmd error -110
ioctl: Connection timed out
Could not read EXT_CSD from /dev/mmcblk0
I have implemented a simple app to send ioctl to get card status, which I am able to do fine. (Here I have sent the argument as RCA), if the argument is 0x0 or 0x0001000 its failing to respond and giving time out error.
int send_status(int fd, __u32 *response)
{
int ret = 0;
struct mmc_ioc_cmd idata;
memset(&idata, 0, sizeof(idata));
idata.opcode = MMC_SEND_STATUS;
/* card relative address is shifted by 16 */
idata.arg = (0xaaaa << 16);
idata.flags = MMC_RSP_R1 | MMC_CMD_AC | MMC_RSP_SPI_S1;
ret = ioctl(fd, MMC_IOC_CMD, &idata);
if (ret)
perror("ioctl");
*response = idata.response[0];
return ret;
}
why mmc-utils failing and how to read card CID through ioctl. I do not want to use cat /sys/block/mmcblk0/device/cid for reading CID
When I am sending GEN_CMD (56) kernel is haning??
Please help giving pointers to debug this issue. Thanks in advance.
Regards,
Vamshi G/