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Re: [Qemu-trivial] [PATCH] imx_serial: Generate interrupt on tx empty if
From: |
Michael Tokarev |
Subject: |
Re: [Qemu-trivial] [PATCH] imx_serial: Generate interrupt on tx empty if enabled |
Date: |
Fri, 11 Sep 2015 10:37:12 +0300 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.8.0 |
Can we please have some r-b or ACK for this? :)
20.08.2015 18:52, Guenter Roeck wrote:
> Generate an interrupt if the tx buffer is empty and the tx empty interrupt
> is enabled. This fixes a problem seen when running a Linux image since
> Linux commit 55c3cb1358e ("serial: imx: remove unneeded imx_transmit_buffer()
> from imx_start_tx()"). Linux now waits for the tx empty interrupt before
> starting to send data, causing transmit stalls until there is an interrupt
> for another reason.
>
> Signed-off-by: Guenter Roeck <address@hidden>
> ---
> hw/char/imx_serial.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/hw/char/imx_serial.c b/hw/char/imx_serial.c
> index f3fbc77..8dc791d 100644
> --- a/hw/char/imx_serial.c
> +++ b/hw/char/imx_serial.c
> @@ -145,7 +145,9 @@ static void imx_update(IMXSerialState *s)
> uint32_t flags;
>
> flags = (s->usr1 & s->ucr1) & (USR1_TRDY|USR1_RRDY);
> - if (!(s->ucr1 & UCR1_TXMPTYEN)) {
> + if (s->ucr1 & UCR1_TXMPTYEN) {
> + flags |= (s->uts1 & UTS1_TXEMPTY);
> + } else {
> flags &= ~USR1_TRDY;
> }
>
>
- Re: [Qemu-trivial] [PATCH] imx_serial: Generate interrupt on tx empty if enabled,
Michael Tokarev <=