[PATCH 4.12 09/31] mmc: sunxi: Keep default timing phase settings for new timing mode - Greg Kroah-Hartman

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org, Chen-Yu Tsai <wens@csie.org>,
	Maxime Ripard <maxime.ripard@free-electrons.com>,
	Ulf Hansson <ulf.hansson@linaro.org>
Subject: [PATCH 4.12 09/31] mmc: sunxi: Keep default timing phase settings for new timing mode
Date: Thu,  3 Aug 2017 16:17:39 -0700	[thread overview]
Message-ID: <20170803231737.589838381@linuxfoundation.org> (raw)
In-Reply-To: <20170803231737.202188456@linuxfoundation.org>

4.12-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Chen-Yu Tsai <wens@csie.org>

commit 26cb2be4c7c42644ccd147c786edb9006300ee56 upstream.

The register for the "new timing mode" also has bit fields for setting
output and sample timing phases. According to comments in Allwinner's
BSP kernel, the default values are good enough.

Keep the default values already in the hardware when setting new timing
mode, instead of overwriting the whole register.

Fixes: 9a37e53e451e ("mmc: sunxi: Enable the new timings for the A64 MMC
controllers")
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/mmc/host/sunxi-mmc.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

--- a/drivers/mmc/host/sunxi-mmc.c
+++ b/drivers/mmc/host/sunxi-mmc.c
@@ -793,8 +793,12 @@ static int sunxi_mmc_clk_set_rate(struct
 	}
 	mmc_writel(host, REG_CLKCR, rval);
 
-	if (host->cfg->needs_new_timings)
-		mmc_writel(host, REG_SD_NTSR, SDXC_2X_TIMING_MODE);
+	if (host->cfg->needs_new_timings) {
+		/* Don't touch the delay bits */
+		rval = mmc_readl(host, REG_SD_NTSR);
+		rval |= SDXC_2X_TIMING_MODE;
+		mmc_writel(host, REG_SD_NTSR, rval);
+	}
 
 	ret = sunxi_mmc_clk_set_phase(host, ios, rate);
 	if (ret)
