On Tue, 6 Dec 2011, Geert Uytterhoeven wrote:
Hi Finn,
On Tue, Dec 6, 2011 at 16:13, Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx> wrote:
+static void pmz_interrupt_control(struct uart_pmac_port *uap, int enable)
+{
+ if (enable) {
+ uap->curregs[1] |= INT_ALL_Rx | TxINT_ENAB;
+ if (!ZS_IS_EXTCLK(uap))
+ uap->curregs[1] |= EXT_INT_ENAB;
+ } else {
+ uap->curregs[1] &= ~(EXT_INT_ENAB | TxINT_ENAB | RxINT_MASK);
Should there be a call to zssync() here?
I don't think so. Though I should have mentioned the change in the patch
header.
The old code always did that after disabling interrupts.
pmz_load_zsregs(), pmz_set_termios() and pmz_suspend() don't do it.
sunzilog only does it on sparc64 and only when writing to the data
register or writing command modifiers to the control register ("On 64-bit
sparc we only need to flush single writes to ensure completion.")
I can't find any purpose for control register reads in the chip manual.
The zssync() calls following some WR1 writes originate here:
http://git.kernel.org/?p=linux/kernel/git/tglx/history.git;a=commitdiff;h=9e9d9f693c7def3900725c04c6b64311655eea51
So I don't see any need for control register reads but hopefully Ben can
say for sure.
Reading the patch now I notice that I dropped a pmz_maybe_update_regs() or
pmz_load_zsregs() in the suspend path. I will send a new patch.
Finn
+ }
+ write_zsreg(uap, R1, uap->curregs[1]);
+}
+
static struct tty_struct *pmz_receive_chars(struct uart_pmac_port *uap)
{
struct tty_struct *tty = NULL;
@@ -339,9 +351,7 @@ static struct tty_struct *pmz_receive_ch
return tty;
flood:
- uap->curregs[R1] &= ~(EXT_INT_ENAB | TxINT_ENAB | RxINT_MASK);
- write_zsreg(uap, R1, uap->curregs[R1]);
- zssync(uap);
Cfr. e.g. here.
+ pmz_interrupt_control(uap, 0);
pmz_error("pmz: rx irq flood !\n");
return tty;
}
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
