Re: [PATCH 3/3] [media] cx231xx: only unregister successfully registered i2c adapters

From: Mauro Carvalho Chehab
Date: Wed Aug 09 2017 - 11:04:17 EST


Em Wed, 9 Aug 2017 16:43:03 +0200
Peter Rosin <peda@xxxxxxxxxx> escreveu:

> On 2017-08-09 16:27, Mauro Carvalho Chehab wrote:
> > Em Mon, 31 Jul 2017 15:38:52 +0200
> > Peter Rosin <peda@xxxxxxxxxx> escreveu:
> >
> >> This prevents potentially scary debug messages from the i2c core.
> >>
> >> Signed-off-by: Peter Rosin <peda@xxxxxxxxxx>
> >> ---
> >> drivers/media/usb/cx231xx/cx231xx-core.c | 3 +++
> >> drivers/media/usb/cx231xx/cx231xx-i2c.c | 3 ++-
> >> 2 files changed, 5 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/media/usb/cx231xx/cx231xx-core.c b/drivers/media/usb/cx231xx/cx231xx-core.c
> >> index 46646ecd2dbc..f372ad3917a8 100644
> >> --- a/drivers/media/usb/cx231xx/cx231xx-core.c
> >> +++ b/drivers/media/usb/cx231xx/cx231xx-core.c
> >> @@ -1311,6 +1311,7 @@ int cx231xx_dev_init(struct cx231xx *dev)
> >> dev->i2c_bus[0].i2c_period = I2C_SPEED_100K; /* 100 KHz */
> >> dev->i2c_bus[0].i2c_nostop = 0;
> >> dev->i2c_bus[0].i2c_reserve = 0;
> >> + dev->i2c_bus[0].i2c_rc = -ENODEV;
> >>
> >> /* External Master 2 Bus */
> >> dev->i2c_bus[1].nr = 1;
> >> @@ -1318,6 +1319,7 @@ int cx231xx_dev_init(struct cx231xx *dev)
> >> dev->i2c_bus[1].i2c_period = I2C_SPEED_100K; /* 100 KHz */
> >> dev->i2c_bus[1].i2c_nostop = 0;
> >> dev->i2c_bus[1].i2c_reserve = 0;
> >> + dev->i2c_bus[1].i2c_rc = -ENODEV;
> >>
> >> /* Internal Master 3 Bus */
> >> dev->i2c_bus[2].nr = 2;
> >> @@ -1325,6 +1327,7 @@ int cx231xx_dev_init(struct cx231xx *dev)
> >> dev->i2c_bus[2].i2c_period = I2C_SPEED_100K; /* 100kHz */
> >> dev->i2c_bus[2].i2c_nostop = 0;
> >> dev->i2c_bus[2].i2c_reserve = 0;
> >> + dev->i2c_bus[2].i2c_rc = -ENODEV;
> >>
> >> /* register I2C buses */
> >> errCode = cx231xx_i2c_register(&dev->i2c_bus[0]);
> >> diff --git a/drivers/media/usb/cx231xx/cx231xx-i2c.c b/drivers/media/usb/cx231xx/cx231xx-i2c.c
> >> index 3e49517cb5e0..8ce6b815d16d 100644
> >> --- a/drivers/media/usb/cx231xx/cx231xx-i2c.c
> >> +++ b/drivers/media/usb/cx231xx/cx231xx-i2c.c
> >> @@ -553,7 +553,8 @@ int cx231xx_i2c_register(struct cx231xx_i2c *bus)
> >> */
> >> void cx231xx_i2c_unregister(struct cx231xx_i2c *bus)
> >> {
> >> - i2c_del_adapter(&bus->i2c_adap);
> >> + if (!bus->i2c_rc)
> >> + i2c_del_adapter(&bus->i2c_adap);
> >
> > That doesn't sound right. what happens if i2c_rc is 1 or 2?
> >
> > IMHO, the right would would be, instead:
> >
> > if (bus->i2c_rc >= 0)
> > i2c_del_adapter(&bus->i2c_adap);
>
> In theory, yes. But in practice i2c_add_adapter never returns >0, and is
> also documented so.

Good point. Just applied the patch.
>
> Let me know if you still want an update. In that case I'll also fix the
> precedent present in the context of patch 1/3, i.e.
>
> if (0 != bus->i2c_rc)
> ...
>
> Cheers,
> peda



Thanks,
Mauro