Re: [RFC 1/4] mmc: cqhci: Move CQHCI_ENABLE before setting TDLBA/TDLBAU

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

On 30/08/17 16:04, Ritesh Harjani wrote:
> Without this patch the CQHCI registers are getting reset
> again.
> 
> Signed-off-by: Ritesh Harjani <riteshh@codeaurora.org>
> ---
>  drivers/mmc/host/cqhci.c | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/mmc/host/cqhci.c b/drivers/mmc/host/cqhci.c
> index 8650a13..2a7351c 100644
> --- a/drivers/mmc/host/cqhci.c
> +++ b/drivers/mmc/host/cqhci.c
> @@ -262,6 +262,9 @@ static void __cqhci_enable(struct cqhci_host *cq_host)
>  
>  	cqhci_writel(cq_host, cqcfg, CQHCI_CFG);
>  
> +	cqcfg |= CQHCI_ENABLE;
> +	cqhci_writel(cq_host, cqcfg, CQHCI_CFG);
That doesn't follow the flow in the specification B.6.1. Command Queuing
Initialization Sequence.  Also in B.3.5 Task List, the spec. says "Changing
the value of TDLBA is not allowed when command queue mode is enabled."

So you will need to add a quirk for this.

> +
>  	cqhci_writel(cq_host, lower_32_bits(cq_host->desc_dma_base),
>  		     CQHCI_TDLBA);
>  	cqhci_writel(cq_host, upper_32_bits(cq_host->desc_dma_base),
> @@ -271,10 +274,6 @@ static void __cqhci_enable(struct cqhci_host *cq_host)
>  
>  	cqhci_set_irqs(cq_host, 0);
>  
> -	cqcfg |= CQHCI_ENABLE;
> -
> -	cqhci_writel(cq_host, cqcfg, CQHCI_CFG);
> -
>  	mmc->cqe_on = true;
>  
>  	if (cq_host->ops->enable)
>