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| author | Imre Kaloz <kaloz@openwrt.org> | 2010-08-09 11:27:14 +0000 |
|---|---|---|
| committer | Imre Kaloz <kaloz@openwrt.org> | 2010-08-09 11:27:14 +0000 |
| commit | 6a946aafb5088d998868a5d06eadaf883193ea14 (patch) | |
| tree | 90cfb11c00ba5ca879799523580f25bad8afa28f /target/linux/cns3xxx | |
| parent | 1ab07cd99b9609d734bd2b7f3216a45475239b81 (diff) | |
| download | upstream-6a946aafb5088d998868a5d06eadaf883193ea14.tar.gz upstream-6a946aafb5088d998868a5d06eadaf883193ea14.tar.bz2 upstream-6a946aafb5088d998868a5d06eadaf883193ea14.zip | |
[cns3xxx]: workaround serial hang with SMP enabled
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@22557 3c298f89-4303-0410-b956-a3cf2f4a3e73
Diffstat (limited to 'target/linux/cns3xxx')
| -rw-r--r-- | target/linux/cns3xxx/patches-2.6.31/210-cns3xxx_smp_serial_fix.patch | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/target/linux/cns3xxx/patches-2.6.31/210-cns3xxx_smp_serial_fix.patch b/target/linux/cns3xxx/patches-2.6.31/210-cns3xxx_smp_serial_fix.patch new file mode 100644 index 0000000000..a9b45aefe5 --- /dev/null +++ b/target/linux/cns3xxx/patches-2.6.31/210-cns3xxx_smp_serial_fix.patch @@ -0,0 +1,39 @@ +--- a/drivers/serial/8250.c ++++ b/drivers/serial/8250.c +@@ -1743,6 +1743,7 @@ static void serial8250_backup_timeout(un + unsigned int iir, ier = 0, lsr; + unsigned long flags; + ++ spin_lock_irqsave(&up->port.lock, flags); + /* + * Must disable interrupts or else we risk racing with the interrupt + * based handler. +@@ -1760,10 +1761,8 @@ static void serial8250_backup_timeout(un + * the "Diva" UART used on the management processor on many HP + * ia64 and parisc boxes. + */ +- spin_lock_irqsave(&up->port.lock, flags); + lsr = serial_in(up, UART_LSR); + up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS; +- spin_unlock_irqrestore(&up->port.lock, flags); + if ((iir & UART_IIR_NO_INT) && (up->ier & UART_IER_THRI) && + (!uart_circ_empty(&up->port.info->xmit) || up->port.x_char) && + (lsr & UART_LSR_THRE)) { +@@ -1771,12 +1770,14 @@ static void serial8250_backup_timeout(un + iir |= UART_IIR_THRI; + } + +- if (!(iir & UART_IIR_NO_INT)) +- serial8250_handle_port(up); +- + if (is_real_interrupt(up->port.irq)) + serial_out(up, UART_IER, ier); + ++ spin_unlock_irqrestore(&up->port.lock, flags); ++ ++ if (!(iir & UART_IIR_NO_INT)) ++ serial8250_handle_port(up); ++ + /* Standard timer interval plus 0.2s to keep the port running */ + mod_timer(&up->timer, + jiffies + poll_timeout(up->port.timeout) + HZ / 5); |