From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jisheng.Zhang@synaptics.com (Jisheng Zhang) Date: Mon, 27 Aug 2018 16:20:26 +0800 Subject: [PATCH v5 0/3] solve SDHCI DWC MSHC 128MB DMA boundary limitation Message-ID: <20180827162026.3901de27@xhacker.debian> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org When using DMA, if the DMA addr spans 128MB boundary, we have to split the DMA transfer into two so that each one doesn't exceed the boundary. patch1 adds adma_table_cnt to struct sdhci_host so that driver can control the ADMA table count. patch2 introduces adma_write_desc() hook to struct sdhci_ops so that driver can override it. patch3 finally solves the 128MB boundary limitation. since v4: - add Adrian's ack to patch 1 and patch 2 - address Adrian's comment -- if the boundary is fine, we have to return after writing dma desc once; adma_table_cnt updating could make use of the fact that it's already initialized by the common sdhci code, we just need to tune. since v3: - s/adma_table_num/adma_table_cnt - add comment to adma_table_cnt - make the exported function name without the _ - let sdhci_adma_write_desc() accept &desc param and set the new desc value since v2: - make use of "likely" to check (!len || BOUNDARY_OK(addr, len)) - explictly include for SZ_128M since v1: - fix BOUNDARY_OK macro if addr+len is aligned to 128MB - use DIV_ROUND_UP to cal extra desc num - fix !len for dwcmshc_adma_write_desc() Jisheng Zhang (3): mmc: sdhci: add adma_table_cnt member to struct sdhci_host mmc: sdhci: introduce adma_write_desc() hook to struct sdhci_ops mmc: sdhci-of-dwcmshc: solve 128MB DMA boundary limitation drivers/mmc/host/sdhci-of-dwcmshc.c | 41 ++++++++++++++++++++++ drivers/mmc/host/sdhci.c | 54 +++++++++++++++++------------ drivers/mmc/host/sdhci.h | 7 ++++ 3 files changed, 80 insertions(+), 22 deletions(-) -- 2.18.0