[PATCH 05/72] ARM: i.MX6: select pll3_usb_otg for ldb_di for rev 1.0 chip

[Steve Longerbeam]

On 11/03/2014 12:06 PM, Fabio Estevam wrote:
> On Mon, Nov 3, 2014 at 5:17 PM, Steve Longerbeam
> <steve_longerbeam at mentor.com> wrote:
>
>> Internally we are using Freescale's workaround patch for this problem,
>> but it has a lot of issues, most of which is that it needs to be incorporated
>> into the clk API so that the workaround would be applied whenever the
>> LDB parent mux is changed.
> Could you please post a patch with this approach? It would be really
> nice to have this fixed in mainline.


Hmm, well I reviewed the Freescale patch again, and it won't be so
simple. The patch assumes the ldb_di_clk_sel mux is set to the reset
default mmdc_ch1_axi source, and that's a central premise of the whole
patch. When the workaround is folded into the clk set_parent ops, this
assumption can't be made any more.

I'm not sure I can capably generalize this patch to switch away from any
of the mux sources to any other, avoiding glitch generation, given that there
appears to be so many undocumented pieces in the CCM module. Is there
someone at Freescale who can take this on?

Steve