linux-kernel - [PATCH v1] mmc: block: Disable CMDQ on the ioctl path

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Date:   Tue,  4 May 2021 22:32:09 +0200
From:   Bean Huo <huobean@...il.com>
To:     ulf.hansson@...aro.org, adrian.hunter@...el.com
Cc:     linux-mmc@...r.kernel.org, linux-kernel@...r.kernel.org,
        Bean Huo <beanhuo@...ron.com>,
        Michael Brunner <Michael.Brunner@...tron.com>
Subject: [PATCH v1] mmc: block: Disable CMDQ on the ioctl path

From: Bean Huo <beanhuo@...ron.com>

According to the eMMC Spec:
"When command queuing is enabled (CMDQ Mode En bit in CMDQ_MODE_EN
field is set to ‘1’) class 11 commands are the only method through
which data transfer tasks can be issued. Existing data transfer
commands, namely CMD18/CMD17 and CMD25/CMD24, are not supported when
command queuing is enabled."
which means if CMDQ is enabled, the FFU commands will not be supported.
To fix this issue, just simply disable CMDQ on the ioctl path, and
re-enable CMDQ once ioctl request is completed.

Tested-by: Michael Brunner <Michael.Brunner@...tron.com>
Signed-off-by: Bean Huo <beanhuo@...ron.com>
---
 drivers/mmc/core/block.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index 689eb9afeeed..21fb99883b1e 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -1004,6 +1004,11 @@ static void mmc_blk_issue_drv_op(struct mmc_queue *mq, struct request *req)
 
 	switch (mq_rq->drv_op) {
 	case MMC_DRV_OP_IOCTL:
+		if (card->ext_csd.cmdq_en) {
+			ret = mmc_cmdq_disable(card);
+			if (ret)
+				break;
+		}
 	case MMC_DRV_OP_IOCTL_RPMB:
 		idata = mq_rq->drv_op_data;
 		for (i = 0, ret = 0; i < mq_rq->ioc_count; i++) {
@@ -1014,6 +1019,8 @@ static void mmc_blk_issue_drv_op(struct mmc_queue *mq, struct request *req)
 		/* Always switch back to main area after RPMB access */
 		if (rpmb_ioctl)
 			mmc_blk_part_switch(card, 0);
+		else if (card->reenable_cmdq && !card->ext_csd.cmdq_en)
+			mmc_cmdq_enable(card);
 		break;
 	case MMC_DRV_OP_BOOT_WP:
 		ret = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_BOOT_WP,
-- 
2.25.1