Re: [RFC PATCH 3/4] tty: omap-serial: use threaded interrupt handler
From: Felipe Balbi <hidden>
Date: 2014-08-19 18:58:11
Also in:
linux-arm-kernel, linux-devicetree, linux-omap, lkml
On Tue, Aug 19, 2014 at 02:14:47PM +0200, Frans Klaver wrote:
At 3.6Mbaud, with slightly over 2Mbit/s data coming in, we see 1600 uart rx buffer overflows within 30 seconds. Threading the interrupt handling reduces this to about 170 overflows in 10 minutes.
Can you try Sebastian Siewior's patches for 8250_omap and 8250 dma support ? That should help you a lot.
quoted hunk ↗ jump to hunk
In practice this therefore reduces the need for hardware flow control, meaning the sending side doesn't have to buffer as much either. Signed-off-by: Frans Klaver <redacted> --- drivers/tty/serial/omap-serial.c | 31 ++++++++++++++++++++++++------- 1 file changed, 24 insertions(+), 7 deletions(-)diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c index 14a0167..57664b9 100644 --- a/drivers/tty/serial/omap-serial.c +++ b/drivers/tty/serial/omap-serial.c@@ -575,6 +575,21 @@ static void serial_omap_rdi(struct uart_omap_port *up, unsigned int lsr) } /** + * serial_omap_fast_irq() - schedule interrupt handling + */ +static irqreturn_t serial_omap_fast_irq(int irq, void *dev_id) +{ + struct uart_omap_port *up = dev_id; + unsigned int iir = serial_in(up, UART_IIR); + + if (iir & UART_IIR_NO_INT) + return IRQ_NONE; + + disable_irq_nosync(up->port.irq);
NAK. Either use IRQF_ONESHOT or actually mask the IRQs at the device's registers (basically clearing IER). -- balbi
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