* [PATCH] hw/char/exynos4210_uart: Fix buffer size reporting with FIFO disabled
@ 2021-01-28 3:36 Iris Johnson
2021-02-02 11:07 ` Peter Maydell
0 siblings, 1 reply; 2+ messages in thread
From: Iris Johnson @ 2021-01-28 3:36 UTC (permalink / raw)
To: Iris Johnson
Cc: Peter Maydell, Igor Mitsyanko, open list:All patches CC here,
open list:Exynos, Marc-André Lureau, Paolo Bonzini
Currently the Exynos 4210 UART code always reports available FIFO space
when the backend checks for buffer space. When the FIFO is disabled this
is behavior causes the backend chardev code to replace the data before the
guest can read it.
This patch changes adds the logic to report the capacity properly when the
FIFO is not being used.
Buglink: https://bugs.launchpad.net/qemu/+bug/1913344
Signed-off-by: Iris Johnson <iris@modwiz.com>
---
hw/char/exynos4210_uart.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/hw/char/exynos4210_uart.c b/hw/char/exynos4210_uart.c
index 6361df2ad3..9b21d201b3 100644
--- a/hw/char/exynos4210_uart.c
+++ b/hw/char/exynos4210_uart.c
@@ -553,7 +553,11 @@ static int exynos4210_uart_can_receive(void *opaque)
{
Exynos4210UartState *s = (Exynos4210UartState *)opaque;
- return fifo_empty_elements_number(&s->rx);
+ if (s->reg[I_(UFCON)] & UFCON_FIFO_ENABLE) {
+ return fifo_empty_elements_number(&s->rx);
+ } else {
+ return !(s->reg[I_(UTRSTAT)] & UTRSTAT_Rx_BUFFER_DATA_READY);
+ }
}
static void exynos4210_uart_receive(void *opaque, const uint8_t *buf, int size)
--
2.25.1
^ permalink raw reply related [flat|nested] 2+ messages in thread* Re: [PATCH] hw/char/exynos4210_uart: Fix buffer size reporting with FIFO disabled
2021-01-28 3:36 [PATCH] hw/char/exynos4210_uart: Fix buffer size reporting with FIFO disabled Iris Johnson
@ 2021-02-02 11:07 ` Peter Maydell
0 siblings, 0 replies; 2+ messages in thread
From: Peter Maydell @ 2021-02-02 11:07 UTC (permalink / raw)
To: Iris Johnson
Cc: Igor Mitsyanko, Marc-André Lureau, open list:Exynos,
open list:All patches CC here, Paolo Bonzini
On Thu, 28 Jan 2021 at 03:36, Iris Johnson <iris@modwiz.com> wrote:
>
> Currently the Exynos 4210 UART code always reports available FIFO space
> when the backend checks for buffer space. When the FIFO is disabled this
> is behavior causes the backend chardev code to replace the data before the
> guest can read it.
>
> This patch changes adds the logic to report the capacity properly when the
> FIFO is not being used.
>
> Buglink: https://bugs.launchpad.net/qemu/+bug/1913344
> Signed-off-by: Iris Johnson <iris@modwiz.com>
> ---
> hw/char/exynos4210_uart.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
Applied to target-arm.next, thanks.
-- PMM
^ permalink raw reply [flat|nested] 2+ messages in thread
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2021-01-28 3:36 [PATCH] hw/char/exynos4210_uart: Fix buffer size reporting with FIFO disabled Iris Johnson
2021-02-02 11:07 ` Peter Maydell
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