Hi Stephen,
On Mon, Mar 19, 2012 at 2:16 PM, Stephen Warren swarren@wwwdotorg.org wrote:
On 03/19/2012 02:27 PM, Simon Glass wrote:
This function is made available to board which want to display a message when a panic() occurs before the console is set up. This would otherwise result in a silent hang or reboot.
Boards should call tegra_pre_console_panic() and pass the UARTs which are available and safe for a message, as well as the selected clock and serial multiplier values. Defaults are available as CONFIG_DEFAULT_NS16550_CLK and CONFIG_DEFAULT_NS16550_MULT.
...
diff --git a/arch/arm/cpu/armv7/tegra2/board.c b/arch/arm/cpu/armv7/tegra2/board.c
...
+void tegra_pre_console_panic(int uart_ids, unsigned clock_freq,
- unsigned multiplier, const char *str)
+{
- int baudrate, divisor;
- const u32 *uart_addr;
- /* Enable all permitted UARTs */
- tegra_setup_uarts(uart_ids);
That call honors uart_ids. ...
- /*
- * Now send the string out all the selected UARTs. We don't try all
- * possible configurations, but this could be added if required.
- */
- baudrate = CONFIG_BAUDRATE;
- divisor = (clock_freq + (baudrate * (multiplier / 2))) /
- (multiplier * baudrate);
- for (uart_addr = uart_reg_addr; *uart_addr; uart_addr++) {
Shouldn't this loop also honor uart_ids, and skip sending data to UARTS not in uart_ids? Sure, they aren't set up above, but perhaps they were set up elsewhere in the code and hence are capable of sending out data anyway?
No, my intent was to use the same value but I overlooked it. I will fix this.
- NS16550_t regs = (NS16550_t)*uart_addr;
- const char *s;
- NS16550_init(regs, divisor);
- for (s = str; *s; s++) {
- NS16550_putc(regs, *s);
- if (*s == '\n')
- NS16550_putc(regs, '\r');
- }
- NS16550_putc(regs, '\n');
- NS16550_putc(regs, '\r');
- }
+}
Regards, Simon