[PATCH] mmc: cqhci: clear HALT state after CQE enable

[Adrian Hunter]

On 26/10/2021 10:08, Wenbin Mei wrote:
> While mmc0 enter suspend state, we need halt CQE to send legacy cmd(flush
> cache) and disable cqe, for resume back, we enable CQE and not clear HALT
> state.
> In this case MediaTek mmc host controller will keep the value for HALT
> state after CQE disable/enable flow, so the next CQE transfer after resume
> will be timeout due to CQE is in HALT state, the log as below:
> <4>.(4)[318:kworker/4:1H]mmc0: cqhci: timeout for tag 2
> <4>.(4)[318:kworker/4:1H]mmc0: cqhci: ============ CQHCI REGISTER DUMP ===========
> <4>.(4)[318:kworker/4:1H]mmc0: cqhci: Caps:      0x100020b6 | Version:  0x00000510
> <4>.(4)[318:kworker/4:1H]mmc0: cqhci: Config:    0x00001103 | Control:  0x00000001
> <4>.(4)[318:kworker/4:1H]mmc0: cqhci: Int stat:  0x00000000 | Int enab: 0x00000006
> <4>.(4)[318:kworker/4:1H]mmc0: cqhci: Int sig:   0x00000006 | Int Coal: 0x00000000
> <4>.(4)[318:kworker/4:1H]mmc0: cqhci: TDL base:  0xfd05f000 | TDL up32: 0x00000000
> <4>.(4)[318:kworker/4:1H]mmc0: cqhci: Doorbell:  0x8000203c | TCN:      0x00000000
> <4>.(4)[318:kworker/4:1H]mmc0: cqhci: Dev queue: 0x00000000 | Dev Pend: 0x00000000
> <4>.(4)[318:kworker/4:1H]mmc0: cqhci: Task clr:  0x00000000 | SSC1:     0x00001000
> <4>.(4)[318:kworker/4:1H]mmc0: cqhci: SSC2:      0x00000001 | DCMD rsp: 0x00000000
> <4>.(4)[318:kworker/4:1H]mmc0: cqhci: RED mask:  0xfdf9a080 | TERRI:    0x00000000
> <4>.(4)[318:kworker/4:1H]mmc0: cqhci: Resp idx:  0x00000000 | Resp arg: 0x00000000
> <4>.(4)[318:kworker/4:1H]mmc0: cqhci: CRNQP:     0x00000000 | CRNQDUN:  0x00000000
> <4>.(4)[318:kworker/4:1H]mmc0: cqhci: CRNQIS:    0x00000000 | CRNQIE:   0x00000000
> 
> This change check HALT state after CQE enable, if CQE is in HALT state, we
> will clear it.
> 
> Signed-off-by: Wenbin Mei <wenbin.mei at mediatek.com>
> Cc: stable at vger.kernel.org

Acked-by: Adrian Hunter <adrian.hunter at intel.com>

> ---
>  drivers/mmc/host/cqhci-core.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/mmc/host/cqhci-core.c b/drivers/mmc/host/cqhci-core.c
> index ca8329d55f43..b0d30c35c390 100644
> --- a/drivers/mmc/host/cqhci-core.c
> +++ b/drivers/mmc/host/cqhci-core.c
> @@ -282,6 +282,9 @@ static void __cqhci_enable(struct cqhci_host *cq_host)
>  
>  	cqhci_writel(cq_host, cqcfg, CQHCI_CFG);
>  
> +	if (cqhci_readl(cq_host, CQHCI_CTL) & CQHCI_HALT)
> +		cqhci_writel(cq_host, 0, CQHCI_CTL);
> +
>  	mmc->cqe_on = true;
>  
>  	if (cq_host->ops->enable)
>