[PATCH v5 1/2] drm/bridge: Add Cadence DSI driver

[Tomi Valkeinen]

On 29/01/18 15:14, Boris Brezillon wrote:

>> You don't disable the dsi_sys_clk neither in the ok nor in the error paths.
> 
> Hm, it shouldn't be enabled in the first place: the runtime resume
> hook takes care of enabling it, and we don't need this clock to access
> IP registers (which is all we do in the probe).

Ah, right, you can just use pm_runtime directly to enable the IP.

I was looking at the docs, but it wasn't quite clear to me when exactly
dsi_sys_clk is needed. I take it that you can access registers with just
the dsi_p_clk, but you can't really do anything with the IP without
dsi_sys_clk? If so, I think enabling both dsi_p_clk and dsi_sys_clk in
the runtime PM callbacks is ok.

Alternatively, if dsi_sys_clk is only needed for some specific
functionality, a more correct way would be to enable that clock only
when that operation is performed.

 Tomi

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