Re: [PATCH v3 4/6] clk: imx6: Make the LDB_DI0 and LDB_DI1 clocks read-only

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On Thu, Jul 18, 2019 at 10:25:05AM +0200, Ahmad Fatoum wrote:
> Hello Roland,
> 
> On 18/7/19 10:19, Roland Hieber wrote:
> > On Wed, Jul 17, 2019 at 07:06:02PM +0200, Ahmad Fatoum wrote:
> >> From: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
> >>
> >> Due to incorrect placement of the clock gate cell in the ldb_di[x]_clk
> >> tree, the glitchy parent mux of ldb_di[x]_clk can cause a glitch to
> >> enter the ldb_di_ipu_div divider. If the divider gets locked up, no
> >> ldb_di[x]_clk is generated, and the LVDS display will hang when the
> >> ipu_di_clk is sourced from ldb_di_clk.
> >>
> >> To fix the problem, both the new and current parent of the ldb_di_clk
> >> should be disabled before the switch. As this can not be guaranteed by
> >> the clock framework during runtime, make the ldb_di[x]_sel muxes read-only.
> >> A workaround to set the muxes once during boot could be added to the
> >> kernel or bootloader.
> >>
> >> Signed-off-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
> >> Signed-off-by: Fabio Estevam <fabio.estevam@xxxxxxx>
> >> Signed-off-by: Shawn Guo <shawnguo@xxxxxxxxxx>
> >> [afa: reviewed for barebox]
> >> Reviewed-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
> >> Tested-by: Andrey Smirnov <andrew.smirnov@xxxxxxxxx>
> >> [afa: ported from Linux kernel commit 03d576f202]
> > 
> > Should this line be further above, or were the lines above all part of
> > the Linux commit?
> 
> The first [afa: is the Demarcation line between kernel and barebox
> commit message. If I moved the second [afa: further up it wouldn't be
> that clear who did what..

Okay, until now I always read the footers like they were appended from
top to bottom chronologically, so first reviewing it for barebox and
only afterwards porting it from Linux doesn't make sense to me :-)
I just haven't met your style in the wild yet.

 - Roland

-- 
Roland Hieber                     | r.hieber@xxxxxxxxxxxxxx     |
Pengutronix e.K.                  | https://www.pengutronix.de/ |
Peiner Str. 6-8, 31137 Hildesheim | Phone: +49-5121-206917-5086 |
Amtsgericht Hildesheim, HRA 2686  | Fax:   +49-5121-206917-5555 |

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