On Tue, Mar 06, 2012 at 07:36:26PM +0100, Enrico Scholz wrote: > When working with DMA backed devices (e.g. framebuffers), writes are > delayed so that 'mw -d /dev/fb0' might not have an immediate effect. > > Behavior after this patch resembles POSIX close(2) functionality which > flushes (blocking) streams on close. > > Drivers which provide 'memmap()' can/should implement a 'flush()' method > which works similarly msync(2) so that buffers can be synchronized on > demand (without low level dma_*_range() operations). Closing such > devices (e.g. when 'mw' or 'bmp' exits) will flush modified memory > content automatically without the need to touch the 'mw', 'bmp' or ... > code. I don't think that's the right way to do it. Framebuffer drivers should use dma_alloc_coherent instead (I know some don't do it atm) Sascha > > Signed-off-by: Enrico Scholz <enrico.scholz@xxxxxxxxxxxxxxxxx> > --- > fs/fs.c | 5 +++++ > include/fcntl.h | 1 + > 2 files changed, 6 insertions(+), 0 deletions(-) > > diff --git a/fs/fs.c b/fs/fs.c > index 13df71c..6ba1da6 100644 > --- a/fs/fs.c > +++ b/fs/fs.c > @@ -714,6 +714,11 @@ int close(int fd) > dev = f->dev; > > fsdrv = (struct fs_driver_d *)dev->driver->type_data; > + > + if (!(f->flags & O_NONBLOCK) && fsdrv->flush) > + /* no way to deal with errors here... */ > + fsdrv->flush(dev, f); > + > errno = fsdrv->close(dev, f); > > put_file(f); > diff --git a/include/fcntl.h b/include/fcntl.h > index aed741e..ffe2f5f 100644 > --- a/include/fcntl.h > +++ b/include/fcntl.h > @@ -13,6 +13,7 @@ > #define O_EXCL 00000200 /* not fcntl */ > #define O_TRUNC 00001000 /* not fcntl */ > #define O_APPEND 00002000 > +#define O_NONBLOCK 00004000 > #define O_DIRECTORY 00200000 /* must be a directory */ > #define O_NOFOLLOW 00400000 /* don't follow links */ > > -- > 1.7.7.6 > > > _______________________________________________ > barebox mailing list > barebox@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/barebox > -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
