Messages in this thread | | | Subject | Re: [PATCH v2] arm64: dts: rockchip: add rk3399 UART DMAs | From | Robin Murphy <> | Date | Thu, 11 Apr 2019 14:48:12 +0100 |
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On 11/04/2019 13:46, Heiko Stuebner wrote: > Hi Robin, > > Am Samstag, 30. März 2019, 00:24:16 CEST schrieb Robin Murphy: >> On 2019-03-27 12:00 pm, Heiko Stuebner wrote: >>> Hi, >>> >>> Am Dienstag, 26. März 2019, 14:49:16 CET schrieb Katsuhiro Suzuki: >>>> Hello Robin, >>>> >>>> Sorry for inconvenience. Since I don't adhere enabling DMA for UARTs, >>>> please revert my patch if you need. >>> >>> I've dropped the patch from my queue now. >>> >>>> BTW, there are DMA properties in RK3328 device-tree like as this patch. >>>> RK3328 UART DMA could not work correctly too...?? >>> >>> I remember Rockcihip dma-controllers having issues with burst-sizes >>> and flushing (there is a no-flushp option in pl330), so it's >>> possible that all share the same error up to rk3399 and rk3328 >>> >>> But so far no-one has shouted regarding the rk3328. >> >> Let me be the first, then, I guess :) >> >> I found an easy way to observe the problem on my 3399, and I've just >> fired up my 3328 box with a 5.0 distro kernel to find that it behaves >> the same. Basically just dump a large pile of text into 'less' on the >> serial console, and scroll through line-by-line - certain lines get >> dropped except for a few characters at the end. >> >> I'll see if I can narrow it down a bit, starting with trying >> broken-flushp... > > did you manage to find time for that test you wanted to do?
Sadly not - I got somewhat distracted by the ethernet thing, and since then I've had too much else going on to follow up on any of my 'for fun' projects :(
If it helps, from a quick look based on what I can remember off-hand, Rockchip UARTs in general have probably been using DMA since 4.19 with d8095f94e195 ("dmaengine: add support for reporting pause and resume separately").
Robin.
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