On Sun, Mar 12, 2017 at 08:40:37PM +0000, Russell King - ARM Linux wrote: > On Sun, Mar 12, 2017 at 01:36:32PM -0700, Steve Longerbeam wrote: > > But hold on, if my logic is correct, then why did the CSI power-off > > get reached in your case, multiple times? Yes I think there is a bug, > > link_notify() is not checking if the link has already been disabled. > > I will fix this. But I'm surprised media core's link_notify handling > > doesn't do this. > > Well, I think there's something incredibly fishy going on here. I > turned that dev_dbg() at the top of the function into a dev_info(), > and I get: > > root@hbi2ex:~# dmesg |grep -A2 imx-ipuv3-csi > [ 53.370949] imx-ipuv3-csi imx-ipuv3-csi.0: power OFF > [ 53.371015] ------------[ cut here ]------------ > [ 53.371075] WARNING: CPU: 0 PID: 1515 at > drivers/staging/media/imx/imx-media-csi.c:806 csi_s_power+0xb8/0xd0 > [imx_media_csi] > -- > [ 53.372624] imx-ipuv3-csi imx-ipuv3-csi.0: power OFF > [ 53.372637] ------------[ cut here ]------------ > [ 53.372663] WARNING: CPU: 0 PID: 1515 at > drivers/staging/media/imx/imx-media-csi.c:806 csi_s_power+0xb8/0xd0 > [imx_media_csi] > > There isn't a power on event being generated before these two power > off events. I don't see a power on event even when I attempt to > start streaming either (which fails due to the lack of bayer > support.)
Found it - my imx219 driver returns '1' from its s_power function when powering up, which triggers a bug in your code - when imx_media_set_power() fails to power up, you call imx_media_set_power() telling it to power everything off - including devices that are already powered off. This is really bad news - s_power() may be called via other paths, such as when the subdev is opened. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net.
