From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vinod Koul Subject: Re: [PATCH v7 0/9] Fix broken DMAFLUSHP on Rockchips platform Date: Mon, 8 Feb 2016 08:41:34 +0530 Message-ID: <20160208031134.GI2531@localhost> References: <1453460812-8498-1-git-send-email-wxt@rock-chips.com> <56AF01B6.6030204@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: <56AF01B6.6030204-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Caesar Wang Cc: Caesar Wang , Heiko Stuebner , Mark Rutland , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Russell King , Pawel Moll , Ian Campbell , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, shawn.lin-TNX95d0MmH7DzftRWevZcw@public.gmane.org, dianders-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org, Rob Herring , linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-rockchip-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Mark Brown , Kumar Gala , dmaengine-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Dan Williams , Sonny Rao , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: devicetree@vger.kernel.org On Mon, Feb 01, 2016 at 02:56:54PM +0800, Caesar Wang wrote: > Hello Vinod, >=20 > Is there any chance apply the DMA patches?:-) I was waiting for any ACKs on ARM patches before I merge this series. > =E5=9C=A8 2016=E5=B9=B401=E6=9C=8822=E6=97=A5 19:06, Caesar Wang =E5=86= =99=E9=81=93: > >This series patches are apply on linus master branch. > >Okay, this series patches verified on my github. > >(https://github.com/Caesar-github/rockchip/commits/for-dma-tests) > > > >Linux version 4.4.0+ (wxt@ubuntu) (Ubuntu/Linaro 4.7.3-12ubuntu1) )= #14 > >SMP Fri Jan 22 18:13:12 CST 2016 > > > >The perious version 6 from Shawn. > >(http://www.spinics.net/lists/dmaengine/msg06606.html) > >I pick them up to go on upstream since Shawn hasn't much time to tra= ck them. > >---- > > > >The purpose of the DMAFLUSHP instruction: > >- Tell the peripheral to clear its status and control registers. > >- Send a message to the peripheral to resend its level status. > > > >There are 3 timings described in PL330 Technical Reference Manual: > >- Timing 1: Burst request, can work well without DMAFLUSHP. > >- Timing 2: Single and burst request, DMAC will ignore the single > > transfer request. This timing happens if there are sing= le > > and burst request. > >- Timing 3: Single transfers for a burst request, DMAC should signal= s > > datype to request the peripheral to flush the contents = of > > any control registers. This timing happens if there is > > not enough MFIFO to places the burst data. > > > >A peripheral may signal a DMA request during the execution of > >DMAFLUSHP instruction, that cause DMA request being ignored by DMAC. > > > >But DMAC and all peripherals on RK3X SoCs DO NOT support DMAFLUSHP. > >It can't send a message to the peripheral to resend DMA request, > >and the peripheral can't acknowledge a flush request from DMAC. > >So all DMA requests should NOT be ignored by DMAC, and DMAC will not > >notify the peripheral to flush. > > > >To fix this problem, we need: > >- Do NOT execute DMAFLUSHP instruction. > >- Timing 2 and timing 3 should not happen. > > > >Because on RK3X SoCs, there are 6 or below channels and 32 MFIFO de= pth > >for DMAC_BUS, and 8 channels and 64 MFIFO depth for DMAC_PERI, it is > >impossible to hit the timing 3 if burst length is equal or less than= 4. > > > >Since the request type signal by the peripheral can only be set by > >software. We can set Rockchip Soc's GRF_PERIDMAC_CON0[2:1] to select= single > >or burst request, if it is set b01, all of the peripharals will sig= nal a brust > >request. So the timing 2 will not happen, too. > > > >So DMAC on RK3X can support single or burst transfer, but can't supp= ort > >mixed transfer. > > > >Because burst transfer is more efficient than single transfer, this = is > >confirmed by our ASIC team, who strongly suggest to use burst transf= er. > >And this is confirmed by Addy's test on RK3288-Pink2 board, the spee= d of > >spi flash burst transfer will increase about two times than single t= ransfer. > >Also, I have tested dw_mmc with pl330 on RK3188 platform to double c= onfirm > >the result. That means burst transfer is reansonable. > > > >So we need a quirk not to execute DMAFLUSHP instruction and to use b= urst > >transfer. > > > >Note: > >- The Rockchip Soc default value of GRF_PERIDMAC_CON0[2:1] is b01. T= o > > support brust transfer, these bits should not be changed in bootl= oader. > > > >Todo: > >remove the patches releated to i2s, that will send them at later. > >- https://patchwork.kernel.org/patch/7399581/ > >- https://patchwork.kernel.org/patch/7399671/ > > > > > >Changes in v7: > >- As vinod comments, fix the subsystem name. > >- modify the subject to be better match. > >- fix the subsystem. > >- fix the subject. > >- fix the subject. > > > >Changes in v6: > >- remove expose quirk and add dma max_burst caps for clients > >- remove expose quirks and add max_burst for dmaengine > >- remove quirks and get dma caps in order to limit burst > > > >Changes in v5: > >- add Mark's tag for spi changes > >- remove unnecessary whitespace change > >- use switch statement for i2s quirk > > > >Changes in v4: > >- remove spi & i2s dts changes and query quirk from dmaengine API > > suggeseted by Mark. > >- fix typo > >- Add dmaengine_get_quirk hook and implement it for pl330 > > > >Changes in v3: > >- add Sunny's tag > >- add more rockchip drivers' changes in this patchset > >- add Reviewed-by: Sonny Rao > >- add Reviewed-by: Sonny Rao > >- add Reviewed-by: Sonny Rao > > > >Changes in v2: > >- amend the author > >- reorder the patches suggested by Doug > >- add Reviewed-by: Doug Anderson for > > rk3288.dtsi patch and arm-pl330.txt patch > >- add Reviewed-by: Doug Anderson > >- amend the author > >- fix Olof's mail address > >- amend the author > >- add Reviewed-by: Doug Anderson > >- amend Olof's mail address > > > >Changes in v1: > >- rename broken-no-flushp to "arm,pl330-broken-no-flushp" suggested > > by Krzysztof. > >- add From original author. > >- remove Sunny's tag > >- rename broken-no-flushp to "arm,pl330-broken-no-flushp" suggested > > by Krzysztof. > >- rename broken-no-flushp to "arm,pl330-broken-no-flushp" suggested > > by Krzysztof. > >- remove Sunny's tag > >- rename broken-no-flushp to "arm,pl330-broken-no-flushp" suggested > > by Krzysztof. > > - remove Sunny's tag > >- rename broken-no-flushp to "arm,pl330-broken-no-flushp" suggested > > by Krzysztof. > > > >Addy Ke (3): > > dmaengine: pl330: add quirk for broken no flushp > > ARM: dts: Add arm, pl330-broken-no-flushp quirk for rk3288 platfo= rm > > spi: rockchip: modify DMA max burst to 1 > > > >Boojin Kim (1): > > dmaengine: pl330: support burst mode for dev-to-mem and mem-to-de= v > > transmit > > > >Caesar Wang (1): > > ARM: dts: add pl330-broken-no-flushp quirk for rk3036 SoCs > > > >Shawn Lin (4): > > dt/bindings: arm-pl330: add description of arm, pl330-broken-no-f= lushp > > ARM: dts: Add arm, pl330-broken-no-flushp quirk for rk3xxx platfo= rm > > dmaengine: core: expose max burst capability to clients > > dmaengine: pl330: add max burst for dmaengine > > > > .../devicetree/bindings/dma/arm-pl330.txt | 1 + > > arch/arm/boot/dts/rk3036.dtsi | 1 + > > arch/arm/boot/dts/rk3288.dtsi | 3 + > > arch/arm/boot/dts/rk3xxx.dtsi | 3 + > > drivers/dma/dmaengine.c | 1 + > > drivers/dma/pl330.c | 106 +++++++++= ++++++------ > > drivers/spi/spi-rockchip.c | 12 ++- > > include/linux/dmaengine.h | 4 + > > 8 files changed, 99 insertions(+), 32 deletions(-) > > >=20 >=20 > --=20 > Thanks, > Caesar >=20 --=20 ~Vinod -- To unsubscribe from this list: send the line "unsubscribe devicetree" i= n the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html