Hi Albert On Mon, 9 Apr 2012, Albert wrote: > Hi, Jonathan & Guennadi > > I'm Albert Wang from Marvell, nice to meet you! Nice to meet you too. > We found there is a soc camera framework in open source, and we made a > Marvell camera driver which based on Soc camera framework + videobuf2. > And now it can serve several Marvell SOC chips, such as MMP2 (PXA688), MMP3 > (PXA2128) and TD (PXA910) which has same CCIC IP. > > But it looks Jonathan had write a Marvell ccic camera driver based on > café-ccic + videobuf2 for MMP2 on OLPC in open source. > > So do you think it?s still OK to push our Marvell camera driver to open > source? A colleague of yours - Kassey Lee - has been working on this driver: http://thread.gmane.org/gmane.linux.drivers.video-input-infrastructure/33775 and it has been agreed, that the camera driver for PXA910 and other SoCs, mentioned above should re-use the same code-base, as the cafe_ccic driver from Jon. One of obstacles has been, that the cafe driver didn't use a standard videobuf scheme, implementing one of its own. Now this has been fixed too, the driver has also been broken down in parts to simplify such code re-use. All this speaks in favour of implementing your driver by using common parts of the marvell-ccic driver. This is also what Kassey has agreed to. Whether or not your new driver will be also using the soc-camera framework is your decision, I think, both ways are possible. Please, try to re-use the marvell-ccic code and report any problems. Thanks Guennadi > Looking for your comments! > Thanks a lot in advance! > > Thanks > Albert Wang > On Sat, Mar 17, 2012 at 7:14 AM, Jonathan Corbet <corbet@xxxxxxx> wrote: > > > The marvell cam driver retained just enough of the owner-tracking logic > > from cafe_ccic to be broken; it could, conceivably, cause the driver to > > release DMA memory while the controller is still active. Simply remove the > > remaining pieces and ensure that the controller is stopped before we free > > things. > > > > Signed-off-by: Jonathan Corbet <corbet@xxxxxxx> > > --- > > drivers/media/video/marvell-ccic/mcam-core.c | 5 +---- > > drivers/media/video/marvell-ccic/mcam-core.h | 1 - > > 2 files changed, 1 insertion(+), 5 deletions(-) > > > > diff --git a/drivers/media/video/marvell-ccic/mcam-core.c > > b/drivers/media/video/marvell-ccic/mcam-core.c > > index 35cd89d..b261182 100644 > > --- a/drivers/media/video/marvell-ccic/mcam-core.c > > +++ b/drivers/media/video/marvell-ccic/mcam-core.c > > @@ -1564,11 +1564,8 @@ static int mcam_v4l_release(struct file *filp) > > singles, delivered); > > mutex_lock(&cam->s_mutex); > > (cam->users)--; > > - if (filp == cam->owner) { > > - mcam_ctlr_stop_dma(cam); > > - cam->owner = NULL; > > - } > > if (cam->users == 0) { > > + mcam_ctlr_stop_dma(cam); > > mcam_cleanup_vb2(cam); > > mcam_ctlr_power_down(cam); > > if (cam->buffer_mode == B_vmalloc && alloc_bufs_at_read) > > diff --git a/drivers/media/video/marvell-ccic/mcam-core.h > > b/drivers/media/video/marvell-ccic/mcam-core.h > > index 917200e..bd6acba 100644 > > --- a/drivers/media/video/marvell-ccic/mcam-core.h > > +++ b/drivers/media/video/marvell-ccic/mcam-core.h > > @@ -107,7 +107,6 @@ struct mcam_camera { > > enum mcam_state state; > > unsigned long flags; /* Buffer status, mainly (dev_lock) > > */ > > int users; /* How many open FDs */ > > - struct file *owner; /* Who has data access (v4l2) */ > > > > /* > > * Subsystem structures. > > -- > > 1.7.9.3 > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-media" in > > the body of a message to majordomo@xxxxxxxxxxxxxxx > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > > --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/ -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
