Re: [RFC PATCH] mmc: cqhci: keep CQE enabled if halt times out

[Adrian Hunter <adrian.hunter@intel.com>]

On 23/06/2026 17:04, Pengpeng Hou wrote:
> cqhci_off() asks the controller to halt before post_disable(), clearing
> mmc->cqe_on and freeing CQE resources. If the halt wait times out, the
> function still continues through that success path even though the
> hardware may still be using the command queue.

CQHCI should be idle when cqhci_off() is used, so it should halt
immediately.  If not, it is a hardware error, but carrying on is
a reasonable option because I/O errors will trigger recovery
later.

> 
> Make cqhci_off() report whether the halt completed and leave the CQE
> state/resources intact when the controller remains stuck on. This keeps
> the existing host-specific ->disable() ordering and is intended as an
> RFC patch because the cqe_disable callback itself has no error return.

Is there a real problem that you are trying to fix?

> 
> Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
> ---
>  drivers/mmc/host/cqhci-core.c | 17 +++++++++++------
>  1 file changed, 11 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/mmc/host/cqhci-core.c b/drivers/mmc/host/cqhci-core.c
> index 178277d90..84846207c 100644
> --- a/drivers/mmc/host/cqhci-core.c
> +++ b/drivers/mmc/host/cqhci-core.c
> @@ -372,14 +372,14 @@ static u32 cqhci_read_ctl(struct cqhci_host *cq_host)
>  	return cqhci_readl(cq_host, CQHCI_CTL);
>  }
>  
> -static void cqhci_off(struct mmc_host *mmc)
> +static bool cqhci_off(struct mmc_host *mmc)
>  {
>  	struct cqhci_host *cq_host = mmc->cqe_private;
>  	u32 reg;
>  	int err;
>  
>  	if (!cq_host->enabled || !mmc->cqe_on || cq_host->recovery_halt)
> -		return;
> +		return true;
>  
>  	if (cq_host->ops->disable)
>  		cq_host->ops->disable(mmc, false);
> @@ -388,15 +388,19 @@ static void cqhci_off(struct mmc_host *mmc)
>  
>  	err = readx_poll_timeout(cqhci_read_ctl, cq_host, reg,
>  				 reg & CQHCI_HALT, 0, CQHCI_OFF_TIMEOUT);
> -	if (err < 0)
> +	if (err < 0) {
>  		pr_err("%s: cqhci: CQE stuck on\n", mmc_hostname(mmc));
> -	else
> -		pr_debug("%s: cqhci: CQE off\n", mmc_hostname(mmc));
> +		return false;
> +	}
> +
> +	pr_debug("%s: cqhci: CQE off\n", mmc_hostname(mmc));
>  
>  	if (cq_host->ops->post_disable)
>  		cq_host->ops->post_disable(mmc);
>  
>  	mmc->cqe_on = false;
> +
> +	return true;
>  }
>  
>  static void cqhci_disable(struct mmc_host *mmc)
> @@ -406,7 +410,8 @@ static void cqhci_disable(struct mmc_host *mmc)
>  	if (!cq_host->enabled)
>  		return;
>  
> -	cqhci_off(mmc);
> +	if (!cqhci_off(mmc))
> +		return;
>  
>  	__cqhci_disable(cq_host);
>