Re: Setting some clocks back to DUMMY fixes spdif output on imx6q wandboard rev B1
From: Nicolin Chen <nicoleotsuka@gmail.com>
Date: 2016-08-29 19:28:24
Also in:
alsa-devel
Added Fabio as I can't test S/PDIF on my board. On Sun, Aug 28, 2016 at 06:00:55PM +0200, Xavi Drudis Ferran wrote:
I was using linux-libre-3.19 (implies no working sdma) with a wandboard quad (Freescale imx6q). Spidf output worked fine. When I upgraded to linux-libre-4.7 spdif output was supressed without any error (precisely, with the same errors about sdma that 3.19 gave). I saw someone else reporting the same elsewhere with linux-4.4 https://forum.digikey.com/thread/34240 (but I don't have a login there) This patch fixes it for me and sound works again on spdif. But I don't know if it can break (or fix?) something for some other boards or kernels or cases... I hardly know what I'm doing.
The commits that might have caused the problem for me might be
commit 833f2cbf7091099baee28136dc68678e974c0ac5
Author: Shengjiu Wang [off-list ref]
Date: Sat Oct 10 18:15:07 2015 +0800
ARM: dts: imx6: change the core clock of spdif
The correct core clock of spdif is SPDIF_GCLK, which is added to
clock tree. So the dts also need to be updated.
Signed-off-by: Shengjiu Wang [off-list ref]
Signed-off-by: Shawn Guo [off-list ref]
(the commit changed more clocks than SPDIF_GCLK)Yes, it seems that it also tried to correct the clock sources as those were not available when adding the S/PDIF support at the first place.
The issue is fixed for me with this patch but I'm not sure what's the best way to help fix any issue someone else may have or what other info or test you might need. Any guidance welcome.
quoted hunk
--- linux-4.7-no-spdif-out/arch/arm/boot/dts/imx6qdl.dtsi 2016-07-25 00:19:43.000000000 +0200 +++ linux-4.7/arch/arm/boot/dts/imx6qdl.dtsi 2016-08-28 17:59:14.276774409 +0200@@ -240,9 +240,9 @@ <&sdma 15 18 0>; dma-names = "rx", "tx"; clocks = <&clks IMX6QDL_CLK_SPDIF_GCLK>, <&clks IMX6QDL_CLK_OSC>, - <&clks IMX6QDL_CLK_SPDIF>, <&clks IMX6QDL_CLK_ASRC>, - <&clks IMX6QDL_CLK_DUMMY>, <&clks IMX6QDL_CLK_ESAI_EXTAL>, - <&clks IMX6QDL_CLK_IPG>, <&clks IMX6QDL_CLK_MLB>, + <&clks IMX6QDL_CLK_SPDIF>, <&clks IMX6QDL_CLK_DUMMY>, + <&clks IMX6QDL_CLK_DUMMY>, <&clks IMX6QDL_CLK_DUMMY>, + <&clks IMX6QDL_CLK_DUMMY>, <&clks IMX6QDL_CLK_DUMMY>, <&clks IMX6QDL_CLK_DUMMY>, <&clks IMX6QDL_CLK_SPBA>; clock-names = "core", "rxtx0", "rxtx1", "rxtx2",
This looks like that you merely revert the SPDIF_GCLK. Would you please do a little debug using "#define DEBUG 1" and check printk from fsl_spdif_probe_txclk() to see the difference between before and after Shengjiu's commit?