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Subject: Re: [PATCH 2/2] mmc: sdhci-of-arasan: Issue DLL reset explicitly
To:     Manish Narani <manish.narani@xilinx.com>,
        <michal.simek@xilinx.com>, <adrian.hunter@intel.com>,
        <ulf.hansson@linaro.org>
CC:     <linux-arm-kernel@lists.infradead.org>,
        <linux-mmc@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <git@xilinx.com>,
        Sai Krishna Potthuri <lakshmi.sai.krishna.potthuri@xilinx.com>
References: <1605507327-106818-1-git-send-email-manish.narani@xilinx.com>
 <1605507327-106818-3-git-send-email-manish.narani@xilinx.com>
From:   Michal Simek <michal.simek@xilinx.com>
Message-ID: <62e86fcf-a50c-6e7a-3eb2-919f0cb34c01@xilinx.com>
Date:   Mon, 16 Nov 2020 08:09:32 +0100
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On 16. 11. 20 7:15, Manish Narani wrote:
> In the current implementation DLL reset will be issued for
> each ITAP and OTAP setting inside ATF, this is creating issues
> in some scenarios and this sequence is not inline with the TRM.
> To fix the issue, DLL reset should be removed from the ATF and
> host driver will request it explicitly.
> This patch update host driver to explicitly request for DLL reset
> before ITAP (assert DLL) and after OTAP (release DLL) settings.
> 
> Fixes: a5c8b2ae2e51 ("mmc: sdhci-of-arasan: Add support for ZynqMP Platform Tap Delays Setup")
> Signed-off-by: Sai Krishna Potthuri <lakshmi.sai.krishna.potthuri@xilinx.com>
> Signed-off-by: Manish Narani <manish.narani@xilinx.com>
> ---
>  drivers/mmc/host/sdhci-of-arasan.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
> index 3ec5ecad637c..e066d8f51954 100644
> --- a/drivers/mmc/host/sdhci-of-arasan.c
> +++ b/drivers/mmc/host/sdhci-of-arasan.c
> @@ -635,6 +635,9 @@ static int sdhci_zynqmp_sdcardclk_set_phase(struct clk_hw *hw, int degrees)
>  	if (ret)
>  		pr_err("Error setting Output Tap Delay\n");
>  
> +	eemi_ops->ioctl(node_id, IOCTL_SD_DLL_RESET,
> +			PM_DLL_RESET_RELEASE, 0, NULL);
> +
>  	return ret;
>  }
>  
> @@ -794,6 +797,9 @@ static int sdhci_versal_sampleclk_set_phase(struct clk_hw *hw, int degrees)
>  	if (host->version < SDHCI_SPEC_300)
>  		return 0;
>  
> +	eemi_ops->ioctl(node_id, IOCTL_SD_DLL_RESET,
> +			PM_DLL_RESET_ASSERT, 0, NULL);
> +
>  	switch (host->timing) {
>  	case MMC_TIMING_MMC_HS:
>  	case MMC_TIMING_SD_HS:
> 

this won't apply. It needs to be fixed.

Thanks,
Michal