Subject: [PATCH 3/3] ARM: imx6: Fix procedure to switch the parent of LDB_DI_CLK

From: [email-masked] (Shawn Guo)
Date: Tue, 20 Jan 2015 14:13:17 +0800

On Fri, Jan 16, 2015 at 10:28:46AM +0100, Dirk Behme wrote:
> On 15.01.2015 17:54, Fabio Estevam wrote:
> >Hi Shawn,
> >
> >On Thu, Jan 8, 2015 at 11:00 AM, Shawn Guo <[email-masked]> wrote:
> >
> >>Before I start reviewing the patch, I would like to know if there is a
> >>formal errata for this issue, including the bug description, recommended
> >>workaround, and affected i.MX6 variants etc.
> >
> >The latest mx6 reference manual available on the web shows the LDB
> >clock gate in the correct position now.
> >
> >It also adds the following note:
> >
> >"NOTE: This clock path is not controlled by a clock gate (CG). For
> >proper clock switching procedures refer to the Clock Switching
> >Multiplexers section."
> >
> >There is no formal errata available.
> >
> >Please consider reviewing this series, as it addresses a real problem
> >that affect many users.
> 
> 
> Just to get a better understanding for the background of this
> series: Are the patches in this series somehow related to Shawn's
> ENGR00318063-x patches in the FSL 3.10.53_1.1.0_ga kernel:
> 
> http://git.freescale.com/git/cgit.cgi/imx/linux-2.6-imx.git/log/?h=imx_3.10.53_1.1.0_ga&qt=grep&q=ENGR00318063
> 
> ?

Fabio,

Look, without the errata for this problem, your customer do not even
know what this patch is for.

Dirk,

Yes, it tries to fix the buggy ldb_di_ipu clock output which doesn't
have a gate between ldb_di_clk_sel and div_3.5_7.  That's also part of
the issues that ENGR00318063-x patches try to address.

Shawn