On Friday, 30 September 2016 17:53:38 BST Alexandre Courbot wrote:
On 09/30/2016 05:46 PM, Thierry Reding wrote:
From: Thierry Reding treding@nvidia.com
For Tegra186 there are currently no UART clocks wired up in device tree. This exposes a regression introduced in commit 50fce1d5d874 ("serial: ns16550: Support clocks via phandle"), which causes the p2771-0000-500 board (and probably any Tegra186-based board as well) to fail to boot.
The reason is that if no clocks property exists, then clk_get_by_index() returns -ENOENT (via fdtdec_parse_phandle_with_args()) rather than -ENODEV as the above-mentioned commit expects.
Fix this by checking for the right error code.
Tested-by: Alexandre Courbot acourbot@nvidia.com
I sent a similar patch ~10 minutes before this one, but Thierry's commit message is clearer than mine (and his handling of -ENODEV probably more correct as well), so let's go with this version!
Hi Thierry & Alexandre,
Apologies for the breakage!
If a DT contains a clock & the UART node references it by phandle then I believe clk_get_by_index() could return -ENODEV via uclass_get_device_by_of_offset & uclass_find_device_by_of_offset. So we probably need to handle both -ENOENT for the "no clocks property" case & - ENODEV for the "clocks property but no driver" case, as Alexandre's patch does?
Thanks, Paul