2017-12-13 19:13:35

by Mauro Carvalho Chehab

[permalink] [raw]
Subject: Re: [PATCH v4 06/12] [media] cxd2880: Add integration layer for the driver

Em Fri, 13 Oct 2017 15:08:34 +0900
<[email protected]> escreveu:

> From: Yasunari Takiguchi <[email protected]>
>
> These functions monitor the driver and watch for task completion.
> This is part of the Sony CXD2880 DVB-T2/T tuner + demodulator driver.

If I understand well, the goal here is to have thread that would
be waking up from time to time, right? Just use the infrastructure
that the Kernel has for it, like a kthread, or timer_setup() & friends.

Take a look at include/linux/timer.h, and just use what's already
defined.


>
> Signed-off-by: Yasunari Takiguchi <[email protected]>
> Signed-off-by: Masayuki Yamamoto <[email protected]>
> Signed-off-by: Hideki Nozawa <[email protected]>
> Signed-off-by: Kota Yonezawa <[email protected]>
> Signed-off-by: Toshihiko Matsumoto <[email protected]>
> Signed-off-by: Satoshi Watanabe <[email protected]>
> ---
>
> [Change list]
> Changes in V4
> drivers/media/dvb-frontends/cxd2880/cxd2880_integ.c
> -removed unnecessary initialization at variable declaration
>
> Changes in V3
> drivers/media/dvb-frontends/cxd2880/cxd2880_integ.c
> -changed cxd2880_atomic_read to atomic_read
> -changed cxd2880_atomic_set to atomic_set
> -modified return code
> -modified coding style of if()
> drivers/media/dvb-frontends/cxd2880/cxd2880_integ.h
> -modified return code
>
> .../media/dvb-frontends/cxd2880/cxd2880_integ.c | 98 ++++++++++++++++++++++
> .../media/dvb-frontends/cxd2880/cxd2880_integ.h | 44 ++++++++++
> 2 files changed, 142 insertions(+)
> create mode 100644 drivers/media/dvb-frontends/cxd2880/cxd2880_integ.c
> create mode 100644 drivers/media/dvb-frontends/cxd2880/cxd2880_integ.h
>
> diff --git a/drivers/media/dvb-frontends/cxd2880/cxd2880_integ.c b/drivers/media/dvb-frontends/cxd2880/cxd2880_integ.c
> new file mode 100644
> index 000000000000..7264fc355d6b
> --- /dev/null
> +++ b/drivers/media/dvb-frontends/cxd2880/cxd2880_integ.c
> @@ -0,0 +1,98 @@
> +/*
> + * cxd2880_integ.c
> + * Sony CXD2880 DVB-T2/T tuner + demodulator driver
> + * integration layer common functions
> + *
> + * Copyright (C) 2016, 2017 Sony Semiconductor Solutions Corporation
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License as published by the
> + * Free Software Foundation; version 2 of the License.
> + *
> + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
> + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
> + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
> + * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
> + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
> + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
> + * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
> + * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
> + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
> + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
> + *
> + * You should have received a copy of the GNU General Public License along
> + * with this program; if not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include "cxd2880_tnrdmd.h"
> +#include "cxd2880_tnrdmd_mon.h"
> +#include "cxd2880_integ.h"
> +
> +int cxd2880_integ_init(struct cxd2880_tnrdmd *tnr_dmd)
> +{
> + int ret;
> + struct cxd2880_stopwatch timer;
> + unsigned int elapsed_time = 0;
> + u8 cpu_task_completed = 0;
> +
> + if (!tnr_dmd)
> + return -EINVAL;
> +
> + ret = cxd2880_tnrdmd_init1(tnr_dmd);
> + if (ret)
> + return ret;
> +
> + ret = cxd2880_stopwatch_start(&timer);
> + if (ret)
> + return ret;
> +
> + while (1) {
> + ret = cxd2880_stopwatch_elapsed(&timer, &elapsed_time);
> + if (ret)
> + return ret;
> +
> + ret =
> + cxd2880_tnrdmd_check_internal_cpu_status(tnr_dmd,
> + &cpu_task_completed);
> + if (ret)
> + return ret;
> +
> + if (cpu_task_completed)
> + break;
> +
> + if (elapsed_time > CXD2880_TNRDMD_WAIT_INIT_TIMEOUT)
> + return -ETIME;
> + ret =
> + cxd2880_stopwatch_sleep(&timer,
> + CXD2880_TNRDMD_WAIT_INIT_INTVL);
> + if (ret)
> + return ret;
> + }
> +
> + ret = cxd2880_tnrdmd_init2(tnr_dmd);
> + if (ret)
> + return ret;
> +
> + return 0;
> +}
> +
> +int cxd2880_integ_cancel(struct cxd2880_tnrdmd *tnr_dmd)
> +{
> + if (!tnr_dmd)
> + return -EINVAL;
> +
> + atomic_set(&tnr_dmd->cancel, 1);
> +
> + return 0;
> +}
> +
> +int cxd2880_integ_check_cancellation(struct cxd2880_tnrdmd *tnr_dmd)
> +{
> + if (!tnr_dmd)
> + return -EINVAL;
> +
> + if (atomic_read(&tnr_dmd->cancel) != 0)
> + return -ECANCELED;
> +
> + return 0;
> +}
> diff --git a/drivers/media/dvb-frontends/cxd2880/cxd2880_integ.h b/drivers/media/dvb-frontends/cxd2880/cxd2880_integ.h
> new file mode 100644
> index 000000000000..2b4fe5c3743b
> --- /dev/null
> +++ b/drivers/media/dvb-frontends/cxd2880/cxd2880_integ.h
> @@ -0,0 +1,44 @@
> +/*
> + * cxd2880_integ.h
> + * Sony CXD2880 DVB-T2/T tuner + demodulator driver
> + * integration layer common interface
> + *
> + * Copyright (C) 2016, 2017 Sony Semiconductor Solutions Corporation
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License as published by the
> + * Free Software Foundation; version 2 of the License.
> + *
> + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
> + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
> + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
> + * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
> + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
> + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
> + * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
> + * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
> + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
> + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
> + *
> + * You should have received a copy of the GNU General Public License along
> + * with this program; if not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#ifndef CXD2880_INTEG_H
> +#define CXD2880_INTEG_H
> +
> +#include "cxd2880_tnrdmd.h"
> +
> +#define CXD2880_TNRDMD_WAIT_INIT_TIMEOUT 500
> +#define CXD2880_TNRDMD_WAIT_INIT_INTVL 10
> +
> +#define CXD2880_TNRDMD_WAIT_AGC_STABLE 100
> +
> +int cxd2880_integ_init(struct cxd2880_tnrdmd *tnr_dmd);
> +
> +int cxd2880_integ_cancel(struct cxd2880_tnrdmd *tnr_dmd);
> +
> +int cxd2880_integ_check_cancellation(struct cxd2880_tnrdmd
> + *tnr_dmd);
> +
> +#endif



Thanks,
Mauro


2017-12-20 01:06:47

by Takiguchi, Yasunari

[permalink] [raw]
Subject: RE: [PATCH v4 06/12] [media] cxd2880: Add integration layer for the driver

Hi, Mauro.

> >
> > These functions monitor the driver and watch for task completion.
> > This is part of the Sony CXD2880 DVB-T2/T tuner + demodulator driver.
>
> If I understand well, the goal here is to have thread that would be waking
> up from time to time, right? Just use the infrastructure that the Kernel
> has for it, like a kthread, or timer_setup() & friends.
>
> Take a look at include/linux/timer.h, and just use what's already defined.

This code is initialize process.
Therefore, it is executed only once and it will not execute other processing at the same time.
We think that the current implementation is enough.
What do you think?
furthermore, we will modify this code by using ktime_foo().

Thanks,
Takiguchi