Microzed issues

List

• [SOLVED] UART

Description:
    UART register contents: timeout=0 rxfifo_level=56, should be timeout=10 rxfifo_level=56
    minicom prints 56 symbols at a time when rxfifo reaches its level.
    remembers all typed symbols
    sometimes the timeout register is set correctly
Possible reason:
    In driver .startup and .termios conflict? Race Reset?
Solution:
    Added a delay after reset - some other functions in the driver also have it - some not. Luck?
Patch:
diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index f214c7f..164e32d 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -704,6 +704,9 @@ static void cdns_uart_set_termios(struct uart_port *port,
        ctrl_reg |= CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST;
        cdns_uart_writel(ctrl_reg, CDNS_UART_CR_OFFSET);
 
+       while (cdns_uart_readl(CDNS_UART_CR_OFFSET) &
+                       (CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST))
+               cpu_relax();
        /*
         * Clear the RX disable and TX disable bits and then set the TX enable
         * bit and RX enable bit to enable the transmitter and receiver.
Links:
    * https://forums.xilinx.com/t5/Zynq-All-Programmable-SoC/Zynq-Uart-timeout-problem/td-p/432016
    * http://www.makelinux.net/ldd3/chp-7-sect-3

• SSH terminal

Description:
    Freezes, lags but remembers all typed symbols
Possible reason:
    UART problem?

• RTC

    Too many messages when rtc is missing
Description:
    3x"hwclock: can't open '/dev/misc/rtc': No such file or directory" in boot log
Possible reason:
    driver

Useful pages

• http://processors.wiki.ti.com/index.php/Enabling_Stack_Dumping_in_Linux_Kernel
• https://lists.yoctoproject.org/pipermail/poky/2015-February/010037.html - change hostname in poky
• http://www.makelinux.net/ldd3/chp-7-sect-3