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From:   Ulf Hansson <ulf.hansson@linaro.org>
Date:   Tue, 28 Aug 2018 13:41:35 +0200
Message-ID: <CAPDyKFpwCx_jReqHBsDh-Sc6zb+4sQGtLsH8QcQ1L=0GUqrcYg@mail.gmail.com>
Subject: Re: [PATCH v6 0/3] solve SDHCI DWC MSHC 128MB DMA boundary limitation
To:     Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Cc:     Adrian Hunter <adrian.hunter@intel.com>,
        "linux-mmc@vger.kernel.org" <linux-mmc@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>
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On 28 August 2018 at 11:45, Jisheng Zhang <Jisheng.Zhang@synaptics.com> wrote:
> 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 v5:
>   - use dma_get_required_mask() to calculate the extra adma_table_cnt
>
> 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))
>   - explicitly include <linux/sizes.h> 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 | 39 +++++++++++++++++++++
>  drivers/mmc/host/sdhci.c            | 54 +++++++++++++++++------------
>  drivers/mmc/host/sdhci.h            |  7 ++++
>  3 files changed, 78 insertions(+), 22 deletions(-)
>
> --
> 2.18.0
>

Applied for next, thanks!

Kind regards
Uffe