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