Hello.
Marc St-Jean wrote:
> diff --git a/arch/mips/pmc-sierra/msp71xx/msp_serial.c
b/arch/mips/pmc-sierra/msp71xx/msp_serial.c
> new file mode 100644
> index 0000000..3b956e9
> --- /dev/null
> +++ b/arch/mips/pmc-sierra/msp71xx/msp_serial.c
> @@ -0,0 +1,185 @@
[...]
> +#ifdef CONFIG_KGDB
> +/*
> + * kgdb uses serial port 1 so the console can remain on port 0.
> + * To use port 0 change the definition to read as follows:
> + * #define DEBUG_PORT_BASE KSEG1ADDR(MSP_UART0_BASE)
> + */
> +#define DEBUG_PORT_BASE KSEG1ADDR(MSP_UART1_BASE)
> +
> +int putDebugChar(char c)
> +{
> + volatile uint32_t *uart = (volatile uint32_t *)DEBUG_PORT_BASE;
> + uint32_t val = (uint32_t)c;
> +
> + local_irq_disable();
> + while (!(uart[5] & 0x20)); /* Wait for TXRDY */
> + uart[0] = val;
> + while (!(uart[5] & 0x20)); /* Wait for TXRDY */
> + local_irq_enable();
Gah, why you decided to put local_irq_enable() there?! KGDB expects
interrupts to be *disabled* while it has control, else some subtle state
corruptions will ensue, and it will eventually lock up. Please remove
these 2 calls completely.
Hmmm, this has been working for several months. I'll remove, retest and
resubmit.
I should probably have said "may". From my experience with KGDBoE though
(well, it's somewhat different KGDB implementation :-) it locks up pretty
quickly because of local_irq_enable() or spin_unlock_irq(). Nevertheless,
enabling interrupts while KGDB has control is undesirable. And look at the
other KGDB serial code inarch/mips/ -- nobody else does this.
Are you aware if this is the case for the "putchar" used by early_printk
as well?
No idea, ask Ralf. ;-)
Thanks,
Marc
WBR, Sergei
