| Submitter | Aleksandr V. Piskunov |
|---|---|
| Date | 2009-10-11 01:01:12 |
| Message ID | <20091011010039.GA4726@moon> |
| Download | mbox | patch |
| Permalink | /patch/52981/ |
| State | Under Review |
| Headers | show |
Comments
On Sun, 2009-10-11 at 04:01 +0300, Aleksandr V. Piskunov wrote: > On Tue, Oct 06, 2009 at 11:11:59AM +0300, Aleksandr V. Piskunov wrote: > > On Tue, Oct 06, 2009 at 11:04:06AM +0300, Aleksandr V. Piskunov wrote: > > > Added FM radio support to Avermedia AVerTV MCE 116 Plus card > > > > > > > What leaves me puzzled, radio only works ok with ivtv newi2c=1 > > > > With default newi2c audio is tinny, metallic, with some strange static. > > Similar problem with pvr-150 was reported years ago, guess issue is still > > unresolved, perhaps something with cx25840.. > > This particular "tinny" audio problem is definitely I2C speed related, to be > more precise, audio only goes bad if i2c-algo-bit is being run with udelay > less than 15, i.e. i2c bus frequency is higher than 30 KHz. > > So with default udelay=10 or udelay=5 (optimal for IR reciever on that board) > radio goes bad. Running with newi2c=1 is ok, but again it isn't optimal for IR > reciever on AVerTV M116. > > I2C reads/writes to cx25840 themself are ok, verified using register readback > after each write/write4. Problem seems to be that with cx25840 register writes > coming too fast on higher i2c bus speed, switching register 0x808 _from_ > TV standard autodetection mode (0xff) _to_ FM radio mode (0xf9) leaves chip > audio detection routine in inconsistent state. > > The only solution I found is to do standard routine (assert_reset + write + > deassert_reset) followed by 50ms delay and another reset. > > Following patch works_for_me, can be improved to only delay/doublereset when > really needed, etc. Andy, could you comment/review? Aleksandr, I will when I get time. This past week and next few weeks are very busy for me for personal (non-linux) reasons. I'll try to get caught up with the patches I still have to rework and then look at this. Obviously, your patch is fairly straightforward and looks OK. I just haven't checked for any implications. The "general" tinny audio problem with the CX25840 on ivtv boards is *always* resolved with an audio microcontroller reset. The problem is the microcontroller may restart its detection loop and tinny audio may return. Can you run FM radio for a long time (a day ?), and see if it ever goes back to tinny audio? Regards, Andy > > diff --git a/linux/drivers/media/video/cx25840/cx25840-core.c b/linux/drivers/media/video/cx25840/cx25840-core.c > --- a/linux/drivers/media/video/cx25840/cx25840-core.c > +++ b/linux/drivers/media/video/cx25840/cx25840-core.c > @@ -626,7 +642,13 @@ > if (state->radio) { > cx25840_write(client, 0x808, 0xf9); > cx25840_write(client, 0x80b, 0x00); > - } > + /* Double reset cx2384x after setting FM radio mode, helps to > + avoid "tinny" audio when ivtv I2C bus is being run on > + frequency higher than 30 KHz */ > + cx25840_and_or(client, 0x810, ~0x01, 0); > + msleep(50); > + cx25840_and_or(client, 0x810, ~0x01, 1); > + } > else if (std & V4L2_STD_525_60) { > /* Certain Hauppauge PVR150 models have a hardware bug > that causes audio to drop out. For these models the > -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sun, 2009-10-11 at 04:01 +0300, Aleksandr V. Piskunov wrote: > On Tue, Oct 06, 2009 at 11:11:59AM +0300, Aleksandr V. Piskunov wrote: > > On Tue, Oct 06, 2009 at 11:04:06AM +0300, Aleksandr V. Piskunov wrote: > > > Added FM radio support to Avermedia AVerTV MCE 116 Plus card > > > > > > > What leaves me puzzled, radio only works ok with ivtv newi2c=1 > > > > With default newi2c audio is tinny, metallic, with some strange static. > > Similar problem with pvr-150 was reported years ago, guess issue is still > > unresolved, perhaps something with cx25840.. > > This particular "tinny" audio problem is definitely I2C speed related, to be > more precise, audio only goes bad if i2c-algo-bit is being run with udelay > less than 15, i.e. i2c bus frequency is higher than 30 KHz. > > So with default udelay=10 or udelay=5 (optimal for IR reciever on that board) > radio goes bad. Running with newi2c=1 is ok, but again it isn't optimal for IR > reciever on AVerTV M116. > > I2C reads/writes to cx25840 themself are ok, verified using register readback > after each write/write4. Problem seems to be that with cx25840 register writes > coming too fast on higher i2c bus speed, switching register 0x808 _from_ > TV standard autodetection mode (0xff) _to_ FM radio mode (0xf9) leaves chip > audio detection routine in inconsistent state. > > The only solution I found is to do standard routine (assert_reset + write + > deassert_reset) followed by 50ms delay and another reset. > > Following patch works_for_me, can be improved to only delay/doublereset when > really needed, etc. Andy, could you comment/review? Aleksandr, Could you provide your Signed-off-by for this patch? I'm going to commit it as is. Thanks, Andy > diff --git a/linux/drivers/media/video/cx25840/cx25840-core.c b/linux/drivers/media/video/cx25840/cx25840-core.c > --- a/linux/drivers/media/video/cx25840/cx25840-core.c > +++ b/linux/drivers/media/video/cx25840/cx25840-core.c > @@ -626,7 +642,13 @@ > if (state->radio) { > cx25840_write(client, 0x808, 0xf9); > cx25840_write(client, 0x80b, 0x00); > - } > + /* Double reset cx2384x after setting FM radio mode, helps to > + avoid "tinny" audio when ivtv I2C bus is being run on > + frequency higher than 30 KHz */ > + cx25840_and_or(client, 0x810, ~0x01, 0); > + msleep(50); > + cx25840_and_or(client, 0x810, ~0x01, 1); > + } > else if (std & V4L2_STD_525_60) { > /* Certain Hauppauge PVR150 models have a hardware bug > that causes audio to drop out. For these models the > > -- > To unsubscribe from this list: send the line "unsubscribe linux-media" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Patch
diff --git a/linux/drivers/media/video/cx25840/cx25840-core.c b/linux/drivers/media/video/cx25840/cx25840-core.c --- a/linux/drivers/media/video/cx25840/cx25840-core.c +++ b/linux/drivers/media/video/cx25840/cx25840-core.c @@ -626,7 +642,13 @@ if (state->radio) { cx25840_write(client, 0x808, 0xf9); cx25840_write(client, 0x80b, 0x00); - } + /* Double reset cx2384x after setting FM radio mode, helps to + avoid "tinny" audio when ivtv I2C bus is being run on + frequency higher than 30 KHz */ + cx25840_and_or(client, 0x810, ~0x01, 0); + msleep(50); + cx25840_and_or(client, 0x810, ~0x01, 1); + } else if (std & V4L2_STD_525_60) { /* Certain Hauppauge PVR150 models have a hardware bug that causes audio to drop out. For these models the