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From: Chen-Yu Tsai <wens@csie.org>
To: Ulf Hansson <ulf.hansson@linaro.org>,
	Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Chen-Yu Tsai <wens@csie.org>,
	linux-mmc@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-sunxi@googlegroups.com,
	Chris Blake <chrisrblake93@gmail.com>,
	stable@vger.kernel.org
Subject: [PATCH 2/3] mmc: sunxi: Filter out unsupported modes declared in the device tree
Date: Sun,  3 Feb 2019 23:56:27 +0800	[thread overview]
Message-ID: <20190203155628.16767-3-wens@csie.org> (raw)
In-Reply-To: <20190203155628.16767-1-wens@csie.org>

The MMC device tree bindings include properties used to signal various
signalling speed modes. Until now the sunxi driver was accepting them
without any further filtering, while the sunxi device trees were not
actually using them.

Since some of the H5 boards can not run at higher speed modes stably,
we are resorting to declaring the higher speed modes per-board.

Regardless, having boards declare modes and blindly following them,
even without proper support in the driver, is generally a bad thing.

Filter out all unsupported modes from the capabilities mask after
the device tree properties have been parsed.

Cc: <stable@vger.kernel.org>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>

---

This should be backported to stable kernels in case people try to run
new device trees (that declare newly supported modes) with old kernels.
---
 drivers/mmc/host/sunxi-mmc.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/mmc/host/sunxi-mmc.c b/drivers/mmc/host/sunxi-mmc.c
index 7415af8c8ff6..a01433012db0 100644
--- a/drivers/mmc/host/sunxi-mmc.c
+++ b/drivers/mmc/host/sunxi-mmc.c
@@ -1415,6 +1415,22 @@ static int sunxi_mmc_probe(struct platform_device *pdev)
 	if (ret)
 		goto error_free_dma;
 
+	/*
+	 * If we don't support delay chains in the SoC, we can't use any
+	 * of the DDR speed modes. Mask them out in case the device
+	 * tree specifies the properties for them, which gets added to
+	 * the caps by mmc_of_parse() above.
+	 */
+	if (!(host->cfg->clk_delays || host->use_new_timings))
+		mmc->caps &= ~(MMC_CAP_3_3V_DDR | MMC_CAP_1_8V_DDR |
+			       MMC_CAP_1_2V_DDR);
+
+	/* TODO: UHS modes untested due to lack of supporting boards */
+	mmc->caps &= ~MMC_CAP_UHS;
+
+	/* TODO: This driver doesn't support HS200 and HS400 modes yet */
+	mmc->caps2 &= ~(MMC_CAP2_HS200 | MMC_CAP2_HS400);
+
 	ret = sunxi_mmc_init_host(host);
 	if (ret)
 		goto error_free_dma;
-- 
2.20.1


  parent reply	other threads:[~2019-02-03 15:56 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-03 15:56 mmc: sunxi: Fix eMMC usage on H5 boards Chen-Yu Tsai
2019-02-03 15:56 ` [PATCH 1/3] mmc: sunxi: Disable HS-DDR mode for H5 eMMC controller by default Chen-Yu Tsai
2019-02-04  9:32   ` Maxime Ripard
2019-02-03 15:56 ` Chen-Yu Tsai [this message]
2019-02-04  9:34   ` [PATCH 2/3] mmc: sunxi: Filter out unsupported modes declared in the device tree Maxime Ripard
2019-02-04 10:16     ` Chen-Yu Tsai
2019-02-04 13:41       ` Maxime Ripard
2019-02-05  8:42         ` Chen-Yu Tsai
2019-02-05  9:51           ` Maxime Ripard
2019-02-03 15:56 ` [PATCH 3/3] arm64: dts: allwinner: h5: libretech-all-h3-cc: Mark eMMC HS-DDR 3.3V capable Chen-Yu Tsai
2019-02-03 15:59 ` [PATCH 0/3] mmc: sunxi: Fix eMMC usage on H5 boards Chen-Yu Tsai

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