Serial console does not display properly for Android 4.4 BSP

[changyuheng]

Hello All:

Default console debug port was set in UART1 for mother board, but  our customer IMX6 board was setting for UART3.

The console shows random unstable since turn UART1 to UART3 as follow:

root@sabresd_6dq:/ #

root@sabresd_6dq:/ #

root@sabresd_6dq:/ #

root@sabresd_6dq:/ #

root@sabresd_6dq:/ # UV

                                            UV

;kdlsrequest_suspend_state: wakeup (3->0) at 26127490005 (2015-01-27 02:54:39.635235336 UTC)

eth0: Freescale FEC PHY driver [Generic PHY] (mii_bus:phy_addr=1:04, irq=-1)

ADDRCONF(NETDEV_UP): eth0: link is not ready

acc_open

acc_release

ehci_fsl_bus_resume begins, DR

US 921600

I have no idea to fix this issue, modify code as follow:

arch/arm/configs/imx6_android_defconfig:

CONFIG_CMDLINE="noinitrd console=ttymxc2,115200 root=/dev/mtdblock2 rw rootfstype=jffs2 ip=off

arch/arm/mach-mx6/board-mx6q_sabresd.c:

static void __init mx6_sabresd_timer_init(void)

#endif

        mx6_clocks_init(32768, 24000000, 0, 0);

-       uart_clk = clk_get_sys("imx-uart.0", NULL);

-       early_console_setup(UART1_BASE_ADDR, uart_clk);

+       uart_clk = clk_get_sys("imx-uart.2", NULL);

+       early_console_setup(UART3_BASE_ADDR, uart_clk);

}

arch/arm/mach-mx6/board-mx6q_sabresd.h:

    MX6Q_PAD_SD4_CLK__UART3_RXD,

    MX6Q_PAD_SD4_CMD__UART3_TXD,

this way is work for ubuntu BSP, so I don't know why android OS has this problem.

Please kindly teach me how to fix it!

Thanks.

[albertlim · Accepted solution]

Thanks Jimmy. The UART setting is fine. I've found the problem, some driver is using the UART3 and I have manage to disable it.

[albertlim]

Hi Public Account,

I am seeing these coming out from UART 3. Have you resolved your problem. I5ts very much appreciated if your could give me some hint

UV

     UV

          UV

               US 921600

                                   US 921600

                                                       US 921600

I would need to know where these came from and how to disable them . The baud rate is 115.2kbps. These looks to me like some command sent out from some driver

Thanks a bunc

Regards

Albert

[jimmychan]

this may help you BSP 13.4.1.04 android boot up issue

[jimmychan]

Please see this.

https://community.freescale.com/thread/308092

please check init.rc.