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From:   Rong Chen <rong.chen@amlogic.com>
To:     Ulf Hansson <ulf.hansson@linaro.org>,
        Neil Armstrong <narmstrong@baylibre.com>,
        Kevin Hilman <khilman@baylibre.com>,
        Jerome Brunet <jbrunet@baylibre.com>,
        Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
        <1131046452@qq.com>, <linux-mmc@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-amlogic@lists.infradead.org>, <linux-kernel@vger.kernel.org>
CC:     <45581586@qq.com>, Rong Chen <rong.chen@amlogic.com>
Subject: [PATCH v2] mmc: meson: Fix usage of meson_mmc_post_req()
Date:   Wed, 16 Feb 2022 20:42:39 +0800
Message-ID: <20220216124239.4007667-1-rong.chen@amlogic.com>
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Precedence: bulk

Currently meson_mmc_post_req() is called in meson_mmc_request() right
after meson_mmc_start_cmd(). This could lead to DMA unmapping before the request
is actually finished.

To fix, don't call meson_mmc_post_req() until meson_mmc_request_done().

Signed-off-by: Rong Chen <rong.chen@amlogic.com>
---
 drivers/mmc/host/meson-gx-mmc.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
index 8f36536cb1b6..58ab9d90bc8b 100644
--- a/drivers/mmc/host/meson-gx-mmc.c
+++ b/drivers/mmc/host/meson-gx-mmc.c
@@ -173,6 +173,8 @@ struct meson_host {
 	int irq;
 
 	bool vqmmc_enabled;
+	bool needs_pre_post_req;
+
 };
 
 #define CMD_CFG_LENGTH_MASK GENMASK(8, 0)
@@ -663,6 +665,8 @@ static void meson_mmc_request_done(struct mmc_host *mmc,
 	struct meson_host *host = mmc_priv(mmc);
 
 	host->cmd = NULL;
+	if (host->needs_pre_post_req)
+		meson_mmc_post_req(mmc, mrq, 0);
 	mmc_request_done(host->mmc, mrq);
 }
 
@@ -880,7 +884,7 @@ static int meson_mmc_validate_dram_access(struct mmc_host *mmc, struct mmc_data
 static void meson_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
 {
 	struct meson_host *host = mmc_priv(mmc);
-	bool needs_pre_post_req = mrq->data &&
+	host->needs_pre_post_req = mrq->data &&
 			!(mrq->data->host_cookie & SD_EMMC_PRE_REQ_DONE);
 
 	/*
@@ -896,22 +900,19 @@ static void meson_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
 		}
 	}
 
-	if (needs_pre_post_req) {
+	if (host->needs_pre_post_req) {
 		meson_mmc_get_transfer_mode(mmc, mrq);
 		if (!meson_mmc_desc_chain_mode(mrq->data))
-			needs_pre_post_req = false;
+			host->needs_pre_post_req = false;
 	}
 
-	if (needs_pre_post_req)
+	if (host->needs_pre_post_req)
 		meson_mmc_pre_req(mmc, mrq);
 
 	/* Stop execution */
 	writel(0, host->regs + SD_EMMC_START);
 
 	meson_mmc_start_cmd(mmc, mrq->sbc ?: mrq->cmd);
-
-	if (needs_pre_post_req)
-		meson_mmc_post_req(mmc, mrq, 0);
 }
 
 static void meson_mmc_read_resp(struct mmc_host *mmc, struct mmc_command *cmd)
-- 
2.25.1