Subject: Re: [RFC 4/4] mmc: sdhci-msm: Handle unexpected interrupt case on
 enabling legacy IRQs on CQE halt
To: Ritesh Harjani <riteshh@codeaurora.org>, ulf.hansson@linaro.org
Cc: linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org,
        stummala@codeaurora.org, asutoshd@codeaurora.org
References: <1504098251-27739-1-git-send-email-riteshh@codeaurora.org>
 <1504098251-27739-5-git-send-email-riteshh@codeaurora.org>
From: Adrian Hunter <adrian.hunter@intel.com>
Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki,
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Message-ID: <3f31712a-56bf-24c1-7823-f33d7c7f665a@intel.com>
Date: Thu, 31 Aug 2017 10:35:19 +0300
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On 30/08/17 16:04, Ritesh Harjani wrote:
> There is a case when enabling the legacy IRQs and halting CQE is
> resuling into a command response interrupt without any command in
> progress. This patch handles such case here.
> 
> Error signature without this patch:-
> mmc0: Got command interrupt 0x00000001 even though no command operation
> was in progress.
> 
> Signed-off-by: Ritesh Harjani <riteshh@codeaurora.org>

Seems fine, but this is a necessary part of enabling i.e. put all the
sdhci-msm changes into one patch.

> ---
>  drivers/mmc/host/sdhci-msm.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
> index baa3409..8fdc2c0 100644
> --- a/drivers/mmc/host/sdhci-msm.c
> +++ b/drivers/mmc/host/sdhci-msm.c
> @@ -1124,10 +1124,21 @@ void sdhci_msm_cqe_enable(struct mmc_host *mmc)
>  void sdhci_msm_cqe_disable(struct mmc_host *mmc, bool recovery)
>  {
>  	struct sdhci_host *host = mmc_priv(mmc);
> +	unsigned long flags;
> +	u32 ctrl;
>  
>  	if (host->flags & SDHCI_USE_64_BIT_DMA)
>  		host->desc_sz = 16;
>  
> +	spin_lock_irqsave(&host->lock, flags);
> +

Could use a comment here.

> +	ctrl = sdhci_readl(host, SDHCI_INT_ENABLE);
> +	ctrl |= SDHCI_INT_RESPONSE;
> +	sdhci_writel(host,  ctrl, SDHCI_INT_ENABLE);
> +	sdhci_writel(host, SDHCI_INT_RESPONSE, SDHCI_INT_STATUS);
> +
> +	spin_unlock_irqrestore(&host->lock, flags);
> +
>  	sdhci_cqe_disable(mmc, recovery);
>  }
>  
>