From: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
To: Jun Nie <jun.nie@linaro.org>
Cc: "ulf.hansson@linaro.org" <ulf.hansson@linaro.org>,
"robh+dt@kernel.org" <robh+dt@kernel.org>,
"mark.rutland@arm.com" <mark.rutland@arm.com>,
"adrian.hunter@intel.com" <adrian.hunter@intel.com>,
"linux-mmc@vger.kernel.org" <linux-mmc@vger.kernel.org>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>
Subject: Re: [PATCH 4/4] mmc: sdhci: Add DMA memory boundary workaround
Date: Tue, 3 Dec 2019 02:47:13 +0000 [thread overview]
Message-ID: <20191203103320.273a7309@xhacker.debian> (raw)
In-Reply-To: <20191202144104.5069-5-jun.nie@linaro.org>
On Mon, 2 Dec 2019 22:41:04 +0800 Jun Nie wrote:
>
>
> DMA memory cannot cross specific boundary for some SDHCI controller,
> such as DesignWare SDHCI controller. Add DMA memory boundary dt
> property and workaround the limitation.
IMHO, the workaround could be implemented in each SDHCI host driver.
eg. drivers/mmc/host/sdhci-of-dwcmshc.c
thanks
>
> Signed-off-by: Jun Nie <jun.nie@linaro.org>
> ---
> drivers/mmc/host/sdhci.c | 20 +++++++++++++++++++-
> drivers/mmc/host/sdhci.h | 1 +
> 2 files changed, 20 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index d8a6c1c91448..56c53fbadd9d 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -763,9 +763,25 @@ static void sdhci_adma_table_pre(struct sdhci_host *host,
> BUG_ON(len > 65536);
>
> /* tran, valid */
> - if (len)
> + if (len) {
> + unsigned int boundary = host->dma_mem_boundary;
> + /*
> + * work around for buffer across mem boundary, split
> + * the buffer.
> + */
> + if (boundary &&
> + ((addr & (boundary - 1)) + len) > boundary) {
> + offset = boundary - (addr & (boundary - 1));
> + __sdhci_adma_write_desc(host, &desc,
> + addr, offset,
> + ADMA2_TRAN_VALID);
> + addr += offset;
> + len -= offset;
> + }
> +
> __sdhci_adma_write_desc(host, &desc, addr, len,
> ADMA2_TRAN_VALID);
> + }
>
> /*
> * If this triggers then we have a calculation bug
> @@ -3634,6 +3650,8 @@ void __sdhci_read_caps(struct sdhci_host *host, const u16 *ver,
> "sdhci-caps-mask", &dt_caps_mask);
> of_property_read_u64(mmc_dev(host->mmc)->of_node,
> "sdhci-caps", &dt_caps);
> + of_property_read_u32(mmc_dev(host->mmc)->of_node,
> + "sdhci-dma-mem-boundary", &host->dma_mem_boundary);
>
> if (of_property_read_u32(mmc_dev(host->mmc)->of_node,
> "sdhci-ctrl-hs400", &host->sdhci_ctrl_hs400))
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index cac4d819f62c..954ac08c4fb0 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -608,6 +608,7 @@ struct sdhci_host {
>
> /* SDHCI_CTRL_HS400 value */
> u32 sdhci_ctrl_hs400;
> + u32 dma_mem_boundary;
>
> unsigned long private[0] ____cacheline_aligned;
> };
> --
> 2.17.1
>
next prev parent reply other threads:[~2019-12-03 2:50 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-02 14:41 [PATCH 0/4] mmc: Add sdhci workaround stability enhencement Jun Nie
2019-12-02 14:41 ` [PATCH 1/4] mmc: sdhci: Add delay after power off Jun Nie
2019-12-03 7:26 ` Adrian Hunter
2019-12-02 14:41 ` [PATCH 2/4] mmc: sdhci: dt: Add DMA boundary and HS400 properties Jun Nie
2019-12-13 23:01 ` Rob Herring
2019-12-17 14:56 ` Jun Nie
2019-12-02 14:41 ` [PATCH 3/4] mmc: sdhci: Set ctrl_hs400 value in dts Jun Nie
2019-12-03 7:52 ` Adrian Hunter
2019-12-02 14:41 ` [PATCH 4/4] mmc: sdhci: Add DMA memory boundary workaround Jun Nie
2019-12-02 17:52 ` Christoph Hellwig
2019-12-03 3:29 ` Jun Nie
2019-12-03 7:36 ` Christoph Hellwig
2019-12-04 6:00 ` Jun Nie
2019-12-04 7:14 ` Jisheng Zhang
2019-12-10 9:36 ` Ulf Hansson
2019-12-03 2:47 ` Jisheng Zhang [this message]
2019-12-03 3:33 ` Jun Nie
2019-12-03 9:05 ` Jisheng Zhang
2019-12-03 9:18 ` Christoph Hellwig
2019-12-03 9:49 ` Jisheng Zhang
2019-12-03 13:06 ` Christoph Hellwig
2019-12-04 7:11 ` Jisheng Zhang
2019-12-03 9:49 ` Jisheng Zhang
2019-12-03 13:04 ` Christoph Hellwig
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