Currently kernel crash randomly when K2L EVM is booted without clk_ignore_unused in the bootargs. This workaround is not needed on other K2 devices such as K2HK and K2E and with this fix, we can remove the workaround altogether. netcp driver on K2L uses linked ram on OSR (On chip Static RAM) and requires the clock to this peripheral enabled for proper functioning. This is the reason for the kernel crash. So add the clock node to fix this issue. While at it, remove the workaround documentation as well. With the fix applied, clk_summary dump shows the clock to OSR enabled. cat /sys/kernel/debug/clk/clk_summary ------cut-------------- tcp3d-1 0 0 399360000 0 0 tcp3d-0 0 0 399360000 0 0 osr 1 1 399360000 0 0 fftc-0 0 0 399360000 0 0 -----cut---------------- Signed-off-by: Murali Karicheri <m-karicheri2@xxxxxx> --- Applies to Linux 4.4-rc2 Documentation/arm/keystone/Overview.txt | 18 ------------------ arch/arm/boot/dts/k2l-netcp.dtsi | 2 +- 2 files changed, 1 insertion(+), 19 deletions(-) diff --git a/Documentation/arm/keystone/Overview.txt b/Documentation/arm/keystone/Overview.txt index f17bc4c..400c0c2 100644 --- a/Documentation/arm/keystone/Overview.txt +++ b/Documentation/arm/keystone/Overview.txt @@ -49,24 +49,6 @@ specified through DTS. Following are the DTS used:- The device tree documentation for the keystone machines are located at Documentation/devicetree/bindings/arm/keystone/keystone.txt -Known issues & workaround -------------------------- - -Some of the device drivers used on keystone are re-used from that from -DaVinci and other TI SoCs. These device drivers may use clock APIs directly. -Some of the keystone specific drivers such as netcp uses run time power -management API instead to enable clock. As this API has limitations on -keystone, following workaround is needed to boot Linux. - - Add 'clk_ignore_unused' to the bootargs env variable in u-boot. Otherwise - clock frameworks will try to disable clocks that are unused and disable - the hardware. This is because netcp related power domain and clock - domains are enabled in u-boot as run time power management API currently - doesn't enable clocks for netcp due to a limitation. This workaround is - expected to be removed in the future when proper API support becomes - available. Until then, this work around is needed. - - Document Author --------------- Murali Karicheri <m-karicheri2@xxxxxx> diff --git a/arch/arm/boot/dts/k2l-netcp.dtsi b/arch/arm/boot/dts/k2l-netcp.dtsi index 01aef23..5acbd0d 100644 --- a/arch/arm/boot/dts/k2l-netcp.dtsi +++ b/arch/arm/boot/dts/k2l-netcp.dtsi @@ -137,7 +137,7 @@ netcp: netcp@26000000 { /* NetCP address range */ ranges = <0 0x26000000 0x1000000>; - clocks = <&papllclk>, <&clkcpgmac>, <&chipclk12>; + clocks = <&clkosr>, <&papllclk>, <&clkcpgmac>, <&chipclk12>; dma-coherent; ti,navigator-dmas = <&dma_gbe 0>, -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html