From 55e3b2f45880faaf06f3c660ca9e8a6d9aa14bce Mon Sep 17 00:00:00 2001 From: Kuninori Morimoto Date: Mon, 9 Dec 2019 15:29:52 +0900 Subject: wiki: Porting wiki: Porting Chat Log Signed-off-by: Kuninori Morimoto --- wiki/Chat_log/20170606-core-chatlog | 124 ++++++++++++++++++++++++++++++++++++ 1 file changed, 124 insertions(+) create mode 100644 wiki/Chat_log/20170606-core-chatlog (limited to 'wiki/Chat_log/20170606-core-chatlog') diff --git a/wiki/Chat_log/20170606-core-chatlog b/wiki/Chat_log/20170606-core-chatlog new file mode 100644 index 0000000..8d5f65f --- /dev/null +++ b/wiki/Chat_log/20170606-core-chatlog @@ -0,0 +1,124 @@ +Core-chat-meeting-2017-06-06 + +10:02 < geertu> Welcome to today's Core Group Chat! +10:03 < geertu> Agenda: +10:03 < geertu> 1. Status updates +10:03 < geertu> 2. Discussion topics +10:03 < geertu> Topic 1. Status updates +10:03 < geertu> A) What have I done since last time +10:03 < geertu> B) What I plan to do till next time +10:03 < geertu> C) Problems I have currently +10:04 < geertu> (tampered with) sort -R said Niklas is first +10:04 < neg> A) No core task ATM +10:04 < neg> B) No plane all time will go to multimeda work next two weeks. +10:04 < neg> C) None +10:04 < neg> EOT +10:05 < neg> s/plane/plan/ +10:05 < geertu> Thank you, Niklas +10:05 < geertu> Next is Marek +10:05 < Marex> A) ULCB U-Boot support patch (tested on dammsans board remotely by booting u-boot from u-boot) B) Submit the ULCB U-Boot patch mainline C) No ULCB available, need to buy one to test flashing the U-Boot instead of booting U-Boot from U-Boot +10:06 < Marex> EOT +10:07 < geertu> I think C is something to discuss with Öpensöurce AB +10:07 < Marex> geertu: correct, already work in progress +10:07 < geertu> Thank you Marek. +10:07 < geertu> Next is Morimoto-san +10:07 < morimoto> A) = B) = C) = NULL, sir +10:08 < geertu> Thank you Morimoto-san! +10:08 < geertu> Next is Mangnus, who is excused. +10:08 < geertu> Next is Laurent, who is on holidays +10:08 < geertu> Next is Jacopo +10:08 < jmondi> A) Add GR-Peach DTS file +10:09 < jmondi> - still discussing RZ pinctrl, found a possible way forward +10:09 < jmondi> B) RZ pinctrl +10:09 < jmondi> C) None +10:09 < jmondi> -- eof -- +10:09 < geertu> s@RZ@RZ/A1@ +10:10 < jmondi> geertu: yes, RZ/A1 +10:10 < geertu> Thank you Jacopo! +10:10 < jmondi> some other RZ are not really RZ :p +10:10 < geertu> Next is Geert +10:10 < geertu> A) What have I done since last time +10:11 < geertu> - Tested H3ULCB with H3 ES2.0 +10:11 < geertu> - Looked into D3 CPG/MSSR +10:11 < geertu> - Made inventory of code under arch/arm/mach-shmobile that still needs DT +10:11 < geertu> conversion, and converted that into a list of tasks for +10:11 < geertu> peripelist/core/todo +10:11 < geertu> - Started looking into suspend/resume for CPG/MSSR and PFC +10:11 < geertu> - Issue is complicated because hardware state is not just lost, but +10:11 < geertu> also different from hardware state on kernel entry during normal +10:11 < geertu> boot. +10:11 < geertu> E.g. on normal boot, U-Boot disables several module clocks. +10:11 < geertu> B) What I plan to do till next time +10:11 < geertu> - Test Salvator XS (when it has arrived) +10:11 < geertu> - Suspend/resume for CPG/MSSR and PFC +10:11 < geertu> - Mark periupport priority < H commits that are in linux-next +10:11 < geertu> C) Problems I have currently +10:11 < geertu> - None +10:11 < geertu> EOT +10:12 < geertu> Next is Simon, who is excused +10:12 < geertu> Next is Shimoda-san +10:12 < shimoda> A) study R-Car D3 CPG spec. and forwarded it to Geert-san :) +10:12 < shimoda> B) investigate R-Car D3 CPG things (especially, I should reply Geert-san's email) +10:12 < shimoda> C) about pause feature in rcar-dmac +10:12 < shimoda> -- EOT --- +10:13 < geertu> Thank you Shimoda-san! +10:13 < geertu> Which brings us to +10:13 < geertu> Topic 2. Discussion topics +10:13 < geertu> Shimoda-san? +10:13 < shimoda> yes +10:14 < geertu> Please explain your problem +10:16 < shimoda> problem is that sh-sci and rcar-dmac implementation is unbalance. I'm not sure it is OK or not +10:17 < geertu> You mean sh-sci calls dmaengine_pause(), while rcar-dmac doesn't implement it? +10:17 < shimoda> sh-sci driver calls dmaengine_pause() but rcar-dmac doesn't have .device_pause() for now +10:18 < shimoda> geertu: yes +10:18 < shimoda> for now, i don't encounter any problem, but this implementation is storange to me +10:18 < shimoda> s/storange/strange/ +10:19 < shimoda> since we don't have any issue, we can use them as-is though :) +10:20 < geertu> The sh-sci driver has a workaround for the absence of .pause(), cfr. the commit that introduced the call (e7327c09def48ccfd204025726f11b57a19a9c24) +10:21 < geertu> But I agree the DMA implementation of sh-sci is far from perfect +10:22 < geertu> So Magnus suggested to make a test case if .device_pause() is really needed or not? +10:22 < shimoda> geertu: yes +10:24 < geertu> Due to the workaround, I think it's not needed now. +10:26 < geertu> IIRC, dmaengine_pause() can be called in interrupt context, while dmaengine_terminate_all() cannot (but it's possible we still violate that) +10:26 < shimoda> geertu: "it's" means .device_pause? +10:26 < geertu> In the mean time, dmaengine_terminate_all() has been deprecated, in gavor of dmaengine_terminate_sync() or dmaengine_terminate_async() +10:27 < geertu> Yes, I meant .device_pause() is not needed due to the workaround +10:27 < geertu> s/gavor/favor/ +10:27 < shimoda> oh, i don't know dmaengine_terminate_all has been deprecated +10:28 < geertu> dmaengine_terminate_async() can be called from interrupt-context, dmaengine_terminate_sync() cannot +10:28 < shimoda> i see +10:28 < geertu> Perhaps Niklas has a better understanding of the modern DMA API? +10:31 < shimoda> about sh-sci point of view, keep the dmaengine_pause calling is better? or should we revert it? +10:31 < neg> not much about the pause implementation I only studied the terminate case +10:33 < geertu> shimoda: The commit that added the pause also added the workaround, so it's better to not revert it +10:35 < neg> but yes terminate_async() is the new API, and my understanding is that you should call device_synchronize() after that at some point to make sure it did terminate +10:35 < shimoda> geertu: about workaround patch, there are the followings? +10:36 < shimoda> 3b96304 serial: sh-sci: Do not terminate DMA engine when race condition occurs +10:36 < shimoda> 1d3db60 serial: sh-sci: Call dma_async_issue_pending when transaction completes +10:36 < shimoda> 371cfed serial: sh-sci: Redirect port interrupts to CPU _only_ when DMA stops +10:36 < geertu> https://patchwork.kernel.org/patch/7289991/ was an attempt to add pause support to rcar-dmac +10:37 < geertu> shimoda: Those are fixes for different issues +10:38 < shimoda> geertu: thank you! but the rcar-dmac patch was rejected in upstream, i think +10:38 < geertu> Indeed, Laurent didn't like it +10:41 < shimoda> i got it. i will check about Laurent-san's opinion in the patchwork later +10:41 < geertu> I'll also add a task to look into pause again +10:43 < shimoda> geertu: thank you for adding it +10:45 < shimoda> so my concern point is cleared, thank you! +10:45 < geertu> good to hear that +10:45 < geertu> Do we have anything else to discuss? +10:46 * Marex might've found VC6 devkit to buy +10:46 < shimoda> nothing from me +10:48 < Marex> geertu: shall I grab the VC6 kit ? +10:48 < geertu> Marex: I suppose you'll receive a Salvator-XS anytime soon? +10:48 < Marex> geertu: I will ? :-) +10:49 < Marex> geertu: anyway, the VC6 kit has RSMA connectors for each output to it's easy to measure the frequency +10:49 < geertu> morimoto: Has it been shipped to Öpensöurce AB yet? +10:49 < Marex> geertu: $186 ... hm +10:50 < geertu> Marex: You forgot to write the driver in Tokyo? ;-) +10:51 < Marex> geertu: I didn't have hardware access there :'-( +10:52 < geertu> Marex: too bad +10:52 < Marex> geertu: still, I feel like grabbing the kit would help also because the i2c is accessible and I can operate it with the clock commander (IDT tool for programming the chip) and I can snoop on the i2c bus to figure out the gaps in the datasheet +10:52 < geertu> Marex: Please check with Magnus +10:53 < Marex> geertu: OK +10:53 < geertu> Then I think we're finished +10:54 < geertu> Thanks for joining, and have a nice continued day -- cgit v1.2.3