Hi Tomi and Tony,
> Am 13.09.2023 um 13:59 schrieb Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>:
>
> On 12/04/2023 10:39, Tony Lindgren wrote:
>> We may not have dsi->dsidev initialized during probe, and that can
>> lead into various dsi related warnings as omap_dsi_host_detach() gets
>> called with dsi->dsidev set to NULL.
>> The warnings can be "Fixed dependency cycle(s)" followed by a
>> WARNING: CPU: 0 PID: 787 at drivers/gpu/drm/omapdrm/dss/dsi.c:4414.
>> Let's fix the warnings by checking for a valid dsi->dsidev.
>> Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
>> ---
>> drivers/gpu/drm/omapdrm/dss/dsi.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>> diff --git a/drivers/gpu/drm/omapdrm/dss/dsi.c b/drivers/gpu/drm/omapdrm/dss/dsi.c
>> --- a/drivers/gpu/drm/omapdrm/dss/dsi.c
>> +++ b/drivers/gpu/drm/omapdrm/dss/dsi.c
>> @@ -4411,7 +4411,7 @@ static int omap_dsi_host_detach(struct mipi_dsi_host *host,
>> {
>> struct dsi_data *dsi = host_to_omap(host);
>> - if (WARN_ON(dsi->dsidev != client))
>> + if (dsi->dsidev && WARN_ON(dsi->dsidev != client))
>> return -EINVAL;
>> cancel_delayed_work_sync(&dsi->dsi_disable_work);
>
> Shouldn't this rather be
>
> if (!dsi->dsidev)
> return 0;
>
> before the if (WARN_ON(dsi->dsidev != client)) line?
Yes you are right. We have a different variant in our Pyra kernel:
What we currently have in our Pyra tree is: https://git.goldelico.com/?p=letux-kernel.git;a=commitdiff;h=5bf7bd64eec1eb924e794e8d6600919f0dae8c5a;hp=27a0cd6263194d1465e9c53293d35f8c8c988f9d
struct dsi_data *dsi = host_to_omap(host);
- if (WARN_ON(dsi->dsidev != client))
+printk("%s\n", __func__);
+
+ if (!dsi->dsidev || WARN_ON(dsi->dsidev != client))
return -EINVAL;
cancel_delayed_work_sync(&dsi->dsi_disable_work);
>
> If dsi->dsidev is NULL, then attach hasn't been called, and we shouldn't do anything in the detach callback either.
>
> With your change we'll end up doing all the work in the detach callback, without ever doing their counterpart in the attach side.
If useful, I can post above mentioned patch (without printk).
BR and thanks,
Nikolaus
