Re: [PATCH v2 2/2] mmc: sdhci-msm: Enable delay circuit calibration clocks

From: Rob Herring
Date: Wed Sep 20 2017 - 17:00:41 EST


On Fri, Sep 15, 2017 at 04:35:24PM -0700, Bjorn Andersson wrote:
> The delay circuit used to support HS400 is calibrated based on two
> additional clocks. When these clocks are not available and
> FF_CLK_SW_RST_DIS is not set in CORE_HC_MODE, reset might fail. But on
> some platforms this doesn't work properly and below dump can be seen in
> the kernel log.
>
> mmc0: Reset 0x1 never completed.
> mmc0: sdhci: ============ SDHCI REGISTER DUMP ===========
> mmc0: sdhci: Sys addr: 0x00000000 | Version: 0x00001102
> mmc0: sdhci: Blk size: 0x00004000 | Blk cnt: 0x00000000
> mmc0: sdhci: Argument: 0x00000000 | Trn mode: 0x00000000
> mmc0: sdhci: Present: 0x01f80000 | Host ctl: 0x00000000
> mmc0: sdhci: Power: 0x00000000 | Blk gap: 0x00000000
> mmc0: sdhci: Wake-up: 0x00000000 | Clock: 0x00000002
> mmc0: sdhci: Timeout: 0x00000000 | Int stat: 0x00000000
> mmc0: sdhci: Int enab: 0x00000000 | Sig enab: 0x00000000
> mmc0: sdhci: AC12 err: 0x00000000 | Slot int: 0x00000000
> mmc0: sdhci: Caps: 0x742dc8b2 | Caps_1: 0x00008007
> mmc0: sdhci: Cmd: 0x00000000 | Max curr: 0x00000000
> mmc0: sdhci: Resp[0]: 0x00000000 | Resp[1]: 0x00000000
> mmc0: sdhci: Resp[2]: 0x00000000 | Resp[3]: 0x00000000
> mmc0: sdhci: Host ctl2: 0x00000000
> mmc0: sdhci: ============================================
>
> Add support for the additional calibration clocks to allow these
> platforms to be configured appropriately.
>
> Cc: Venkat Gopalakrishnan <venkatg@xxxxxxxxxxxxxx>
> Cc: Ritesh Harjani <riteshh@xxxxxxxxxxxxxx>
> Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> ---
>
> Changes since v1:
> - Add new clocks to DT binding
>
> Documentation/devicetree/bindings/mmc/sdhci-msm.txt | 2 ++

Acked-by: Rob Herring <robh@xxxxxxxxxx>

> drivers/mmc/host/sdhci-msm.c | 12 +++++++++++-
> 2 files changed, 13 insertions(+), 1 deletion(-)