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Re: [PATCH v2 7/7] hw/arm/exynos4210: Connect serial port DMA busy signa
Re: [PATCH v2 7/7] hw/arm/exynos4210: Connect serial port DMA busy signals with pl330
Mon, 20 Jan 2020 13:59:41 +0000
On Sat, 18 Jan 2020 at 16:42, Guenter Roeck <address@hidden> wrote:
> The Exynos4210 serial driver uses an interrupt line to signal if receive
> data is available. Connect that interrupt with the DMA controller's
> 'peripheral busy' gpio pin to stop the DMA if there is no more receive
> data available. Without this patch, receive DMA runs wild and fills the
> entire receive DMA buffer with invalid data.
> Signed-off-by: Guenter Roeck <address@hidden>
> v2: Context changes; improved description
> This patch has an outstanding review comment, suggesting that
> uart and pl330 device states should be kept in Exynos4210State.
> I did not address this comment for a number of reasons.
> It looks like the problem is hypothetical, the problem may
> apply to all devices created in exynos4210_realize(), and I am
> not sure I understand what would need to be done to fix
> the problem for good (ie for all devices created in the same
> function which have the same problem). Overall, I think that
> handling this situation would be better left for a separate patch.
> hw/arm/exynos4210.c | 42 +++++++++++++++++++++++++++++-------------
> 1 file changed, 29 insertions(+), 13 deletions(-)
Reviewed-by: Peter Maydell <address@hidden>
[PATCH v2 3/7] hw/char/exynos4210_uart: Convert to support tracing, Guenter Roeck, 2020/01/18
[PATCH v2 4/7] hw/char/exynos4210_uart: Implement post_load function, Guenter Roeck, 2020/01/18
[PATCH v2 5/7] hw/char/exynos4210_uart: Implement Rx FIFO level triggers and timeouts, Guenter Roeck, 2020/01/18
[PATCH v2 7/7] hw/arm/exynos4210: Connect serial port DMA busy signals with pl330, Guenter Roeck, 2020/01/18
- Re: [PATCH v2 2/7] hw/arm/exynos4210: Fix DMA initialization, (continued)
[PATCH v2 6/7] hw/char/exynos4210_uart: Add receive DMA support, Guenter Roeck, 2020/01/18
- Re: [PATCH v2 7/7] hw/arm/exynos4210: Connect serial port DMA busy signals with pl330,
Peter Maydell <=