Hi Chris,

On Tue, 11 Nov 2025 19:39:25 +0000
Chris Brandt <[email protected]> wrote:

> Hi Hugo,
> 
> On Tue, Nov 11, 2025 1:23 PM, Hugo Villeneuve wrote:
> > I still don't know on which tree you based your patchset, just to be sure 
> > that I am not missing anything.
> >
> > Should it work on 6.17.7 stable tree or torvalds/master tree?
> 
> I am using 
> https://git.kernel.org/pub/scm/linux/kernel/git/geert/renesas-devel.git
> 
> I have been testing with v6-18-rc2   (I have not pulled in the latest yet)
> 
> Chris

You still haven't provided the base-commit. There is a ton of branches in
renesas-devel.git, so it is not easy to determine the branch/commit you used 
for your patchset.
By providing base-commit, you will save everyone a lot of trouble.

I tried to apply your patches on branch renesas-geert/master,
using base-commit: 211ddde0823f

I am using 4 lanes and a 24-bit panel, and a clock of 59MHz.

Here is the relevant logs (I added some custom debug messages):

[    1.508000] rzg2l_cpg_dsi_div_set_divider(): dsi->lanes = 0
[    1.508183] rzg2l_cpg_dsi_div_set_divider(): divider = 0
[    1.513538] rzg2l_cpg_dsi_div_set_divider(): target  = 1
...
[    1.641377] [drm] cmdline forces connector DSI-1 panel_orientation to 3
[    1.649264] [drm] Initialized rzg2l-du 1.0.0 for 10890000.display on minor 1
[    1.656353] rzg2l-du 10890000.display: [drm] Device 10890000.display probed
[    1.680646] rzg2l-du 10890000.display: [drm] fb0: rzg2l-dudrmfb frame buffer 
device
[    1.688840] rzg2l-cpg 11010000.clock-controller: 
rzg2l_cpg_get_foutpostdiv_rate(): rate = 59000000
[    1.701034] rzg2l-cpg 11010000.clock-controller: 
rzg2l_cpg_get_foutpostdiv_rate(): dsi_div_ab_desired = 0
[    1.701042] rzg2l-cpg 11010000.clock-controller: 
rzg2l_cpg_get_foutpostdiv_rate(): hsclk = 0
[    1.714490] rzg2l-cpg 11010000.clock-controller: hsclk out of range
[    1.714501] rzg2l-cpg 11010000.clock-controller: 
rzg2l_cpg_get_foutpostdiv_rate(): rate = 59000000
[    1.729171] rzg2l-cpg 11010000.clock-controller: 
rzg2l_cpg_get_foutpostdiv_rate(): dsi_div_ab_desired = 0
[    1.729178] rzg2l-cpg 11010000.clock-controller: 
rzg2l_cpg_get_foutpostdiv_rate(): hsclk = 0
[    1.729184] rzg2l-cpg 11010000.clock-controller: hsclk out of range
[    1.729190] rzg2l-cpg 11010000.clock-controller: 
rzg2l_cpg_get_foutpostdiv_rate(): rate = 59000000
[    1.729196] rzg2l-cpg 11010000.clock-controller: 
rzg2l_cpg_get_foutpostdiv_rate(): dsi_div_ab_desired = 0
[    1.729201] rzg2l-cpg 11010000.clock-controller: 
rzg2l_cpg_get_foutpostdiv_rate(): hsclk = 0
...

The problem seems to be that dsi_div_ab_desired is not properly initialized,
because the number of lanes is uninitialized (0) at this time, and therefore
rzg2l_cpg_dsi_div_set_divider() gets called with its first parameter as zero.

Like I said, it also happens on 6.17.7 stable tree. If I remove your patches, 
everything is fine.

Hugo.

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