From mboxrd@z Thu Jan 1 00:00:00 1970 From: yibin.gong@nxp.com (Robin Gong) Date: Mon, 11 Jun 2018 12:09:22 +0000 Subject: [PATCH v3 0/6] add virt-dma support for imx-sdma In-Reply-To: <1528714877.2842.3.camel@pengutronix.de> References: <1528729173-28684-1-git-send-email-yibin.gong@nxp.com>, <1528714877.2842.3.camel@pengutronix.de> Message-ID: <8C06065A-DC99-4DA8-BF97-0C3BFE95C080@nxp.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Lucas, Thank for your report, I tested it only on SPI, will update to you after try on uart tomorrow. > ? 2018?6?11????7:01?Lucas Stach ??? > > Hi Robin, > > this series breaks serial DMA for me. I wasn't able to dig in deeper > yet. Please let me know if you can test/reproduce at your side, if not > I'll try to find some time to collect some more debug info. > > Regards, > Lucas > > Am Montag, den 11.06.2018, 22:59 +0800 schrieb Robin Gong: >> The legacy sdma driver has below limitations or drawbacks: >> 1. Hardcode the max BDs number as "PAGE_SIZE / sizeof(*)", and alloc >> one page size for one channel regardless of only few BDs needed >> most time. But in few cases, the max PAGE_SIZE maybe not enough. >> 2. One SDMA channel can't stop immediatley once channel disabled which >> means SDMA interrupt may come in after this channel terminated.There >> are some patches for this corner case such as commit "2746e2c389f9", >> but not cover non-cyclic. >> >> The common virt-dma overcomes the above limitations. It can alloc bd >> dynamically and free bd once this tx transfer done. No memory wasted or >> maximum limititation here, only depends on how many memory can be requested >> from kernel. For No.2, such issue can be workaround by checking if there >> is available descript("sdmac->desc") now once the unwanted interrupt >> coming. At last the common virt-dma is easier for sdma driver maintain. >> >> Change from v2: >> 1. include Sascha's patch to make the main patch easier to review. >> Thanks Sacha. >> 2. remove useless 'desc'/'chan' in struct sdma_channe. >> >> Change from v1: >> 1. split v1 patch into 5 patches. >> 2. remove some unnecessary condition check. >> 3. remove unnecessary 'pending' list. >> >> Robin Gong (5): >> dmaengine: imx-sdma: add virt-dma support >> Revert "dmaengine: imx-sdma: fix pagefault when channel is disabled >> during interrupt" >> dmaengine: imx-sdma: remove usless lock >> dmaengine: imx-sdma: remove the maximum limation for bd numbers >> dmaengine: imx-sdma: add sdma_transfer_init to decrease code overlap >> >> drivers/dma/Kconfig | 1 + >> drivers/dma/imx-sdma.c | 392 ++++++++++++++++++++++++++++--------------------- >> 2 files changed, 227 insertions(+), 166 deletions(-) >> >> -- >> 2.7.4 >> >> Robin Gong (5): >> dmaengine: imx-sdma: add virt-dma support >> Revert "dmaengine: imx-sdma: fix pagefault when channel is disabled >> during interrupt" >> dmaengine: imx-sdma: remove usless lock >> dmaengine: imx-sdma: remove the maximum limation for bd numbers >> dmaengine: imx-sdma: add sdma_transfer_init to decrease code overlap >> >> Sascha Hauer (1): >> dmaengine: imx-sdma: factor out a struct sdma_desc from struct >> sdma_channel >> >> drivers/dma/Kconfig | 1 + >> drivers/dma/imx-sdma.c | 391 ++++++++++++++++++++++++++++--------------------- >> 2 files changed, 226 insertions(+), 166 deletions(-) >>