From: Grond <[email protected]> On the pandora, only McSPI1 (spi0) is actually used. Because the device tree defaults in arch/arm/boot/dts/omap3.dtsi leave all of the mcspi interfaces enabled, the DMA channels which the device tree assigns to them cannot be used for anything else. This is a problem because OMAP3's sDMA controller can only have 32 DMA channels configured at any one time.
So when we try to use (for example) the McBSP subsystem (which is required for sound) it doesn't work because we've already exhausted our available DMA channels. Fix this by disabling mcspi[2-4] on the pandora device tree. Signed-off-by: Grond <[email protected]> Signed-off-by: H. Nikolaus Schaller <[email protected]> --- .../boot/dts/ti/omap/omap3-pandora-common.dtsi | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/arch/arm/boot/dts/ti/omap/omap3-pandora-common.dtsi b/arch/arm/boot/dts/ti/omap/omap3-pandora-common.dtsi index a0116823ffdef..b4acab1625212 100644 --- a/arch/arm/boot/dts/ti/omap/omap3-pandora-common.dtsi +++ b/arch/arm/boot/dts/ti/omap/omap3-pandora-common.dtsi @@ -693,6 +693,23 @@ lcd_in: endpoint { }; +/* + * Only mcspi1 is used on the pandora, the others do not surface on the board + * due to pinmux configuration. disable the unused ones so that they do not + * consume DMA channels + */ +&mcspi2 { + status = "disabled"; +}; + +&mcspi3 { + status = "disabled"; +}; + +&mcspi4 { + status = "disabled"; +}; + /* n/a - used as GPIOs */ &mcbsp1 { }; -- 2.50.1 (Apple Git-155)
