On 2013-07-05 17:47, H Hartley Sweeten wrote:
On Friday, July 05, 2013 8:30 AM, Ian Abbott wrote:
`comedi_alloc_spriv()` allocates private storage for a comedi subdevice
and sets the `SRF_FREE_SPRIV` flag in the `runflags` member of the
subdevice to allow the private storage to be automatically freed when
the comedi device is being cleaned up. Unfortunately, the flag gets
clobbered by `do_cmd_ioctl()` which calls
`comedi_set_subdevice_runflags()` with a mask value `~0` and only the
`SRF_USER` and `SRF_RUNNING` flags set, all the other SRF flags being
cleared.
Change the calls to `comedi_set_subdevice_runflags()` that currently use
a mask value of `~0` to use a more relevant mask value. For
`do_cmd_ioctl()`, the relevant SRF flags are `SRF_USER`, `SRF_ERROR` and
`SRF_RUNNING`. (At one time, `SRF_RT` would be included in that set of
flags, but it is no longer used.)
Signed-off-by: Ian Abbott <abbotti@xxxxxxxxx>
---
Currently, this change is only needed for 3.11-rc.
---
drivers/staging/comedi/comedi_fops.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c
index 0794aac..ade8964 100644
--- a/drivers/staging/comedi/comedi_fops.c
+++ b/drivers/staging/comedi/comedi_fops.c
@@ -543,7 +543,8 @@ void *comedi_alloc_spriv(struct comedi_subdevice *s, size_t size)
{
s->private = kzalloc(size, GFP_KERNEL);
if (s->private)
- comedi_set_subdevice_runflags(s, ~0, SRF_FREE_SPRIV);
+ comedi_set_subdevice_runflags(s, SRF_FREE_SPRIV,
+ SRF_FREE_SPRIV);
As we have discussed previously, this function is only called during a board
(*attach). During the attach the spinlock on the runflags should not be needed
so this could be simplified to just:
s->runflags |= SRF_FREE_SPRIV;
A bit subjective, but I'd count that as two changes.
return s->private;
}
EXPORT_SYMBOL_GPL(comedi_alloc_spriv);
@@ -1489,7 +1490,8 @@ static int do_cmd_ioctl(struct comedi_device *dev,
if (async->cmd.flags & TRIG_WAKE_EOS)
async->cb_mask |= COMEDI_CB_EOS;
- comedi_set_subdevice_runflags(s, ~0, SRF_USER | SRF_RUNNING);
+ comedi_set_subdevice_runflags(s, SRF_USER | SRF_ERROR | SRF_RUNNING,
+ SRF_USER | SRF_RUNNING);
This one makes sense. But to avoid any future similar problems, maybe
comedi_set_subdevice_runflags() should just mask the 'mask' so that
the SRF_FREE_SPRIV flag is never cleared. This flag is a "special" runflag
in that it is not really part of the subdevice running state.
ret = s->do_cmd(dev, s);
> if (ret == 0)
Or maybe get rid of SRF_FREE_SPRIV and use some other flag that doesn't
use the runflags member. It's only there because runflags has lots of
unused bits. We could make it smaller and add a bool bitfield member.
--
-=( Ian Abbott @ MEV Ltd. E-mail: <abbotti@xxxxxxxxx> )=-
-=( Tel: +44 (0)161 477 1898 FAX: +44 (0)161 718 3587 )=-
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