[PATCH] clk: eswin: Keep the TCU AXI clock enabled

[Brian Masney]

Hi Han,

> The SMMU TCU needs its AXI clock for DMA, even in bypass mode. No driver
> claims this clock, so clk_disable_unused() gates it and DMA through the
> SMMU stalls. On the HiFive Premier P550, this hangs firmware loading of
> an RX550 graphics card.
> 
> Mark the clock as critical.
> 
> Fixes: cd44f127c1d4 ("clk: eswin: Add eic7700 clock driver")
> Signed-off-by: Han Gao <gaohan at iscas.ac.cn>

Cc: stable

> ---
> Tested on the HiFive Premier P550 with an RX550 graphics card:
> 
> - Without this patch, amdgpu stalls while loading the RX550 firmware
>   and CPUs can no longer be halted.
> - With only the TCU AXI clock kept enabled (the TCU configuration clock
>   is still managed normally), amdgpu initializes and the IB ring tests
>   pass without any manual register writes.

Please include these details in the commit message above the ---.

I can take this patch, however I'd ideally like to see a review from
Xuyang or someone at eswin first.

Brian

-- 
Brian Masney <masneyb at kernel.org>