Messages in this thread Patch in this message | | | From | "Leonardo G. Veiga" <> | Subject | [PATCH] sdhci-esdhc-imx: fix bus-width for 1-bit operation. | Date | Tue, 1 Nov 2016 13:58:25 -0200 |
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From: Leonardo Graboski Veiga <leonardo.veiga@toradex.com>
The 1-bit operation mode, enabled by seeting the 'bus-width' property of the device tree 'esdhc' node to <1>, not work while using SD card.
The behavior is only noticed when only the data pin 0 is connected to the hardware. A series of kernel errors are printed to the console, all of them returning the following error message followed by some explanation: mmcblk0: error -84 transferring data
If four data lines are connected, it ignores the device-tree property and works in 4-bit mode of operation without errors. The hardware used for testing does not support 8-bit mode.
Check the 'bus-width' property and if set to <1>, enable the SDHCI_QUIRK_FORCE_1_BIT_DATA quirk.
Signed-off-by: Leonardo Graboski Veiga <leonardo.veiga@toradex.com> --- drivers/mmc/host/sdhci-esdhc-imx.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c index c9fbc4c3..88d7d22 100644 --- a/drivers/mmc/host/sdhci-esdhc-imx.c +++ b/drivers/mmc/host/sdhci-esdhc-imx.c @@ -1003,6 +1003,10 @@ sdhci_esdhc_imx_probe_dt(struct platform_device *pdev, host->quirks2 |= SDHCI_QUIRK2_NO_1_8_V; } + if (!of_property_read_u32(np, "bus-width", &boarddata->max_bus_width) + && boarddata->max_bus_width == 1) + host->quirks |= SDHCI_QUIRK_FORCE_1_BIT_DATA; + /* call to generic mmc_of_parse to support additional capabilities */ ret = mmc_of_parse(host->mmc); if (ret) -- 2.7.4
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