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List:       linux-mmc
Subject:    [PATCH] mmc: core: sdio: hold retuning if sdio in 1-bit mode
From:       haibo.chen () nxp ! com
Date:       2023-08-30 9:39:22
Message-ID: 20230830093922.3095850-1-haibo.chen () nxp ! com
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From: Haibo Chen <haibo.chen@nxp.com>

tuning only support in 4-bit mode or 8 bit mode, so in 1-bit mode,
need to hold retuning.

Find this issue when use manual tuning method on imx93. When system
resume back, SDIO WIFI try to switch back to 4 bit mode, first will
trigger retuning, and all tuning command failed.

Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
---
 drivers/mmc/core/sdio.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
index f64b9ac76a5c..5914516df2f7 100644
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -1089,8 +1089,14 @@ static int mmc_sdio_resume(struct mmc_host *host)
 		}
 		err = mmc_sdio_reinit_card(host);
 	} else if (mmc_card_wake_sdio_irq(host)) {
-		/* We may have switched to 1-bit mode during suspend */
+		/*
+		 * We may have switched to 1-bit mode during suspend,
+		 * need to hold retuning, because tuning only supprt
+		 * 4-bit mode or 8 bit mode.
+		 */
+		mmc_retune_hold_now(host);
 		err = sdio_enable_4bit_bus(host->card);
+		mmc_retune_release(host);
 	}
 
 	if (err)
-- 
2.34.1

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