[PATCH 4.19 17/35] mmc: cqhci: clear HALT state after CQE enable

[Greg Kroah-Hartman]

From: Wenbin Mei <wenbin.mei@xxxxxxxxxxxx>

commit 92b18252b91de567cd875f2e84722b10ab34ee28 upstream.

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@xxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Fixes: a4080225f51d ("mmc: cqhci: support for command queue enabled host")
Link: https://lore.kernel.org/r/20211026070812.9359-1-wenbin.mei@xxxxxxxxxxxx
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/mmc/host/cqhci.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/mmc/host/cqhci.c
+++ b/drivers/mmc/host/cqhci.c
@@ -281,6 +281,9 @@ static void __cqhci_enable(struct cqhci_
 
 	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)