Re: [PATCH] ipoctal: clear break interrupt as soon as it occurs

From: Samuel Iglesias Gonsálvez
Date: Mon Sep 01 2014 - 08:42:49 EST


On Mon, 2014-09-01 at 13:49 +0200, Federico Vaga wrote:
> In some condition we receive the break interrupt but nothing is putted
> in the Rx FIFO and the correspondend bit in the status register is not
> set. Thus, no-one clear the interrupt and the handler will be called
> forever.
>
> This patch clear the break interrupt as soon as it occurs. Then, if the
> break character '\0' is putted in the fifo we will manage it.
>
> We can also unmask the Break interrupt but its bit in ISR is still set
> on break. So I think is better to keep the registers clean.
>
> Signed-off-by: Federico Vaga <federico.vaga@xxxxxxx>
> ---
> drivers/ipack/devices/ipoctal.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/ipack/devices/ipoctal.c b/drivers/ipack/devices/ipoctal.c
> index e41bef0..90b96a1b 100644
> --- a/drivers/ipack/devices/ipoctal.c
> +++ b/drivers/ipack/devices/ipoctal.c
> @@ -151,7 +151,6 @@ static void ipoctal_irq_rx(struct ipoctal_channel *channel, u8 sr)
> flag = TTY_FRAME;
> }
> if (sr & SR_RECEIVED_BREAK) {
> - iowrite8(CR_CMD_RESET_BREAK_CHANGE, &channel->regs->w.cr);
> channel->stats.rcv_break++;
> flag = TTY_BREAK;
> }
> @@ -196,6 +195,9 @@ static void ipoctal_irq_channel(struct ipoctal_channel *channel)
> isr = ioread8(&channel->block_regs->r.isr);
> sr = ioread8(&channel->regs->r.sr);
>
> + if (isr & (IMR_DELTA_BREAK_A | IMR_DELTA_BREAK_B))
> + iowrite8(CR_CMD_RESET_BREAK_CHANGE, &channel->regs->w.cr);
> +
> if ((sr & SR_TX_EMPTY) && (channel->nb_bytes == 0)) {
> iowrite8(CR_DISABLE_TX, &channel->regs->w.cr);
> /* In case of RS-485, change from TX to RX when finishing TX.

Acked-by: Samuel Iglesias Gonsalvez <siglesias@xxxxxxxxxx>

Thanks for the patch!

Greg, Would you mind picking this patch through your char-misc tree?

Sam

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