eMMC-5.1 JESD84-B51 Spec (Section 6.6.39.1), mentions "Prior to
enabling command queuing, the block size shall be set to 512 B.
Device may respond with an error to CMD46/CMD47 if block size
is not 512 B".

This patch fixes the sequence to follow exact as per the spec.

Signed-off-by: Sowjanya Komatineni <[email protected]>
---
 drivers/mmc/host/cqhci.c | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/drivers/mmc/host/cqhci.c b/drivers/mmc/host/cqhci.c
index 159270e947cf..f701342e7212 100644
--- a/drivers/mmc/host/cqhci.c
+++ b/drivers/mmc/host/cqhci.c
@@ -248,6 +248,9 @@ static void __cqhci_enable(struct cqhci_host *cq_host)
                cqhci_writel(cq_host, cqcfg, CQHCI_CFG);
        }
 
+       if (cq_host->ops->enable)
+               cq_host->ops->enable(mmc);
+
        cqcfg &= ~(CQHCI_DCMD | CQHCI_TASK_DESC_SZ);
 
        if (mmc->caps2 & MMC_CAP2_CQE_DCMD)
@@ -273,9 +276,6 @@ static void __cqhci_enable(struct cqhci_host *cq_host)
 
        mmc->cqe_on = true;
 
-       if (cq_host->ops->enable)
-               cq_host->ops->enable(mmc);
-
        /* Ensure all writes are done before interrupts are enabled */
        wmb();
 
@@ -561,6 +561,7 @@ static int cqhci_request(struct mmc_host *mmc, struct 
mmc_request *mrq)
        int tag = cqhci_tag(mrq);
        struct cqhci_host *cq_host = mmc->cqe_private;
        unsigned long flags;
+       u32 cqcfg = 0;
 
        if (!cq_host->enabled) {
                pr_err("%s: cqhci: not enabled\n", mmc_hostname(mmc));
@@ -579,8 +580,19 @@ static int cqhci_request(struct mmc_host *mmc, struct 
mmc_request *mrq)
                        pr_err("%s: cqhci: CQE failed to exit halt state\n",
                               mmc_hostname(mmc));
                }
+               /* Configuration must not be changed while enabled */
+               cqcfg = cqhci_readl(cq_host, CQHCI_CFG);
+               if (cqcfg & CQHCI_ENABLE) {
+                       cqcfg &= ~CQHCI_ENABLE;
+                       cqhci_writel(cq_host, cqcfg, CQHCI_CFG);
+               }
+
                if (cq_host->ops->enable)
                        cq_host->ops->enable(mmc);
+
+               cqcfg |= CQHCI_ENABLE;
+               cqhci_writel(cq_host, cqcfg, CQHCI_CFG);
+
        }
 
        if (mrq->data) {
-- 
2.7.4

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