I have a problem regarding booting from MMC on my custom IMX6Dual board, using U-Boot version branch imx_v2017.03_4.9.51_imx8_beta2.
On most of my boards the boot process works. I can select my mmc dev 1 and get the following trace log:
switch to partitions #0, OK
mmc1(part 0) is current device
But on some of the boards, selecting mmc dev 1 fails with the following trace logs:
mmc_init: -110, time 128
This is the code that fails in drivers/mmc/mmc.c in function static int mmc_startup(struct mmc *mmc):
/* Put the Card in Identify Mode */
cmd.cmdidx = mmc_host_is_spi(mmc) ? MMC_CMD_SEND_CID :
MMC_CMD_ALL_SEND_CID; /* cmd not supported in spi */
cmd.resp_type = MMC_RSP_R2;
cmd.cmdarg = 0;
err = mmc_send_cmd(mmc, &cmd, NULL);
} while (err && retries-- > 0);
This problem did not occur on my boards with the U-Boot v2014 version.
How can I resolve this issue?