Re: [PATCH] rtl28xxu: correct usb_clear_halt() usage

[poma <pomidorabelisima@gmail.com>]

On 09/01/2012 03:54 PM, Antti Palosaari wrote:
> It is not allowed to call usb_clear_halt() after urbs are submitted.
> That causes oops sometimes. Move whole streaming_ctrl() logic to
> power_ctrl() in order to avoid wrong usb_clear_halt() use. Also,
> configuring streaming endpoint in streaming_ctrl() sounds like a
> little bit wrong as it is aimed for control stream gate.
> 
> Reported-by: Hin-Tak Leung <htl10@users.sourceforge.net>
> Signed-off-by: Antti Palosaari <crope@iki.fi>
> ---
>  drivers/media/usb/dvb-usb-v2/rtl28xxu.c | 55 +++++++++++++++------------------
>  1 file changed, 25 insertions(+), 30 deletions(-)
> 
> diff --git a/drivers/media/usb/dvb-usb-v2/rtl28xxu.c b/drivers/media/usb/dvb-usb-v2/rtl28xxu.c
> index e29fca2..7d11c5d 100644
> --- a/drivers/media/usb/dvb-usb-v2/rtl28xxu.c
> +++ b/drivers/media/usb/dvb-usb-v2/rtl28xxu.c
> @@ -825,37 +825,10 @@ err:
>  	return ret;
>  }
>  
> -static int rtl28xxu_streaming_ctrl(struct dvb_frontend *fe , int onoff)
> -{
> -	int ret;
> -	u8 buf[2];
> -	struct dvb_usb_device *d = fe_to_d(fe);
> -
> -	dev_dbg(&d->udev->dev, "%s: onoff=%d\n", __func__, onoff);
> -
> -	if (onoff) {
> -		buf[0] = 0x00;
> -		buf[1] = 0x00;
> -		usb_clear_halt(d->udev, usb_rcvbulkpipe(d->udev, 0x81));
> -	} else {
> -		buf[0] = 0x10; /* stall EPA */
> -		buf[1] = 0x02; /* reset EPA */
> -	}
> -
> -	ret = rtl28xx_wr_regs(d, USB_EPA_CTL, buf, 2);
> -	if (ret)
> -		goto err;
> -
> -	return ret;
> -err:
> -	dev_dbg(&d->udev->dev, "%s: failed=%d\n", __func__, ret);
> -	return ret;
> -}
> -
>  static int rtl2831u_power_ctrl(struct dvb_usb_device *d, int onoff)
>  {
>  	int ret;
> -	u8 gpio, sys0;
> +	u8 gpio, sys0, epa_ctl[2];
>  
>  	dev_dbg(&d->udev->dev, "%s: onoff=%d\n", __func__, onoff);
>  
> @@ -878,11 +851,15 @@ static int rtl2831u_power_ctrl(struct dvb_usb_device *d, int onoff)
>  		gpio |= 0x04; /* GPIO2 = 1, LED on */
>  		sys0 = sys0 & 0x0f;
>  		sys0 |= 0xe0;
> +		epa_ctl[0] = 0x00; /* clear stall */
> +		epa_ctl[1] = 0x00; /* clear reset */
>  	} else {
>  		gpio &= (~0x01); /* GPIO0 = 0 */
>  		gpio |= 0x10; /* GPIO4 = 1 */
>  		gpio &= (~0x04); /* GPIO2 = 1, LED off */
>  		sys0 = sys0 & (~0xc0);
> +		epa_ctl[0] = 0x10; /* set stall */
> +		epa_ctl[1] = 0x02; /* set reset */
>  	}
>  
>  	dev_dbg(&d->udev->dev, "%s: WR SYS0=%02x GPIO_OUT_VAL=%02x\n", __func__,
> @@ -898,6 +875,14 @@ static int rtl2831u_power_ctrl(struct dvb_usb_device *d, int onoff)
>  	if (ret)
>  		goto err;
>  
> +	/* streaming EP: stall & reset */
> +	ret = rtl28xx_wr_regs(d, USB_EPA_CTL, epa_ctl, 2);
> +	if (ret)
> +		goto err;
> +
> +	if (onoff)
> +		usb_clear_halt(d->udev, usb_rcvbulkpipe(d->udev, 0x81));
> +
>  	return ret;
>  err:
>  	dev_dbg(&d->udev->dev, "%s: failed=%d\n", __func__, ret);
> @@ -972,6 +957,14 @@ static int rtl2832u_power_ctrl(struct dvb_usb_device *d, int onoff)
>  			goto err;
>  
>  
> +		/* streaming EP: clear stall & reset */
> +		ret = rtl28xx_wr_regs(d, USB_EPA_CTL, "\x00\x00", 2);
> +		if (ret)
> +			goto err;
> +
> +		ret = usb_clear_halt(d->udev, usb_rcvbulkpipe(d->udev, 0x81));
> +		if (ret)
> +			goto err;
>  	} else {
>  		/* demod_ctl_1 */
>  		ret = rtl28xx_rd_reg(d, SYS_DEMOD_CTL1, &val);
> @@ -1006,6 +999,10 @@ static int rtl2832u_power_ctrl(struct dvb_usb_device *d, int onoff)
>  		if (ret)
>  			goto err;
>  
> +		/* streaming EP: set stall & reset */
> +		ret = rtl28xx_wr_regs(d, USB_EPA_CTL, "\x10\x02", 2);
> +		if (ret)
> +			goto err;
>  	}
>  
>  	return ret;
> @@ -1182,7 +1179,6 @@ static const struct dvb_usb_device_properties rtl2831u_props = {
>  	.tuner_attach = rtl2831u_tuner_attach,
>  	.init = rtl28xxu_init,
>  	.get_rc_config = rtl2831u_get_rc_config,
> -	.streaming_ctrl = rtl28xxu_streaming_ctrl,
>  
>  	.num_adapters = 1,
>  	.adapter = {
> @@ -1204,7 +1200,6 @@ static const struct dvb_usb_device_properties rtl2832u_props = {
>  	.tuner_attach = rtl2832u_tuner_attach,
>  	.init = rtl28xxu_init,
>  	.get_rc_config = rtl2832u_get_rc_config,
> -	.streaming_ctrl = rtl28xxu_streaming_ctrl,
>  
>  	.num_adapters = 1,
>  	.adapter = {
> 

OK, after patching with this one from http://goo.gl/5wtpT there is no
OOPS, but this happened[1][2]:
1. mythtv-setup version: fixes/0.25 [v0.25.2-3-gf0e2ad8-dirty]:
…
   E  DVBChan(1:/dev/dvb/adapter0/frontend0): Getting Frontend
uncorrected block count failed.
eno: Operation not supported (95)
2012-09-01 17:08:20.577044 W  DVBSM(/dev/dvb/adapter0/frontend0): Cannot
count Uncorrected Blocks
eno: Operation not supported (95)
…
2. tzap/femon:
…
status 1f | signal 2f2f | snr 00f2 | ber 0000001e | unc 00000033 |
FE_HAS_LOCK
status 1f | signal 2f2f | snr 00f3 | ber 0000000b | unc 00000033 |
FE_HAS_LOCK
status 1f | signal 2f2f | snr 00f1 | ber 00000000 | unc 00000033 |
FE_HAS_LOCK
…
…
Problem retrieving frontend information: Operation not supported
status SCVYL | signal  18% | snr   0% | ber 19 | unc 1 | FE_HAS_LOCK
Problem retrieving frontend information: Operation not supported
status SCVYL | signal  18% | snr   0% | ber 7 | unc 1 | FE_HAS_LOCK
Problem retrieving frontend information: Operation not supported
status SCVYL | signal  18% | snr   0% | ber 54 | unc 1 | FE_HAS_LOCK
…

Cheers,
poma