2019-09-29 08:06:02

by Andrei Koshkosh

Subject: [PATCH 1/1] media: dvbsky: use a single mutex and state buffers for all R/W ops

Signed-off-by: Andrei Koshkosh <[email protected]>
---
drivers/media/usb/dvb-usb-v2/dvbsky.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/media/usb/dvb-usb-v2/dvbsky.c b/drivers/media/usb/dvb-usb-v2/dvbsky.c
index c41e10b..6a118a0 100644
--- a/drivers/media/usb/dvb-usb-v2/dvbsky.c
+++ b/drivers/media/usb/dvb-usb-v2/dvbsky.c
@@ -22,7 +22,6 @@ MODULE_PARM_DESC(disable_rc, "Disable inbuilt IR receiver.");
DVB_DEFINE_MOD_OPT_ADAPTER_NR(adapter_nr);

struct dvbsky_state {
- struct mutex stream_mutex;
u8 ibuf[DVBSKY_BUF_LEN];
u8 obuf[DVBSKY_BUF_LEN];
u8 last_lock;
@@ -61,16 +60,18 @@ static int dvbsky_stream_ctrl(struct dvb_usb_device *d, u8 onoff)
{
struct dvbsky_state *state = d_to_priv(d);
int ret;
- u8 obuf_pre[3] = { 0x37, 0, 0 };
- u8 obuf_post[3] = { 0x36, 3, 0 };
+ static u8 obuf_pre[3] = { 0x37, 0, 0 };
+ static u8 obuf_post[3] = { 0x36, 3, 0 };

- mutex_lock(&state->stream_mutex);
- ret = dvbsky_usb_generic_rw(d, obuf_pre, 3, NULL, 0);
+ mutex_lock(&d->usb_mutex);
+ memcpy(state->obuf, obuf_pre, 3);
+ ret = dvb_usbv2_generic_write_locked(d, state->obuf, 3);
if (!ret && onoff) {
msleep(20);
- ret = dvbsky_usb_generic_rw(d, obuf_post, 3, NULL, 0);
+ memcpy(state->obuf, obuf_post, 3);
+ ret = dvb_usbv2_generic_write_locked(d, state->obuf, 3);
}
- mutex_unlock(&state->stream_mutex);
+ mutex_unlock(&d->usb_mutex);
return ret;
}

@@ -599,7 +600,6 @@ static int dvbsky_init(struct dvb_usb_device *d)
if (ret)
return ret;
*/
- mutex_init(&state->stream_mutex);

state->last_lock = 0;

--
2.7.4

2019-09-29 22:08:56

by JP

Subject: Re: [PATCH 1/1] media: dvbsky: use a single mutex and state buffers for all R/W ops

This works very well for me.
(and please see unrelated comment below)

On 9/29/19 10:04 AM, Andrei Koshkosh wrote:
> Signed-off-by: Andrei Koshkosh <[email protected]>
> ---
> drivers/media/usb/dvb-usb-v2/dvbsky.c | 16 ++++++++--------
> 1 file changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/media/usb/dvb-usb-v2/dvbsky.c b/drivers/media/usb/dvb-usb-v2/dvbsky.c
> index c41e10b..6a118a0 100644
> --- a/drivers/media/usb/dvb-usb-v2/dvbsky.c
> +++ b/drivers/media/usb/dvb-usb-v2/dvbsky.c
> @@ -22,7 +22,6 @@ MODULE_PARM_DESC(disable_rc, "Disable inbuilt IR receiver.");
> DVB_DEFINE_MOD_OPT_ADAPTER_NR(adapter_nr);
>
> struct dvbsky_state {
> - struct mutex stream_mutex;
> u8 ibuf[DVBSKY_BUF_LEN];
> u8 obuf[DVBSKY_BUF_LEN];
> u8 last_lock;
> @@ -61,16 +60,18 @@ static int dvbsky_stream_ctrl(struct dvb_usb_device *d, u8 onoff)
> {
> struct dvbsky_state *state = d_to_priv(d);
> int ret;
> - u8 obuf_pre[3] = { 0x37, 0, 0 };
> - u8 obuf_post[3] = { 0x36, 3, 0 };
> + static u8 obuf_pre[3] = { 0x37, 0, 0 };
> + static u8 obuf_post[3] = { 0x36, 3, 0 };
>
> - mutex_lock(&state->stream_mutex);
> - ret = dvbsky_usb_generic_rw(d, obuf_pre, 3, NULL, 0);
> + mutex_lock(&d->usb_mutex);
> + memcpy(state->obuf, obuf_pre, 3);
> + ret = dvb_usbv2_generic_write_locked(d, state->obuf, 3);
> if (!ret && onoff) {
> msleep(20);
> - ret = dvbsky_usb_generic_rw(d, obuf_post, 3, NULL, 0);
> + memcpy(state->obuf, obuf_post, 3);
> + ret = dvb_usbv2_generic_write_locked(d, state->obuf, 3);
> }
> - mutex_unlock(&state->stream_mutex);
> + mutex_unlock(&d->usb_mutex);
> return ret;
> }
>
> @@ -599,7 +600,6 @@ static int dvbsky_init(struct dvb_usb_device *d)
> if (ret)
> return ret;
> */
commented-out code has call to non-existing function.

> - mutex_init(&state->stream_mutex);
>
> state->last_lock = 0;
>
Thanks,
Jan Pieter.

2019-11-08 18:33:12

by Stefan Brüns

Subject: Re: [PATCH 1/1] media: dvbsky: use a single mutex and state buffers for all R/W ops

On Freitag, 8. November 2019 19:15:13 CET Andrei Koshkosh wrote:
> Signed-off-by: Andrei Koshkosh <[email protected]>

Do not claim to be author of something you have not written.

This is mostly commit 7d95fb746c4e "media: dvbsky: use just one mutex for
serializing device R/W ops" originally from Mauro and later reverted.

Regards,

Stefan

> ---
> drivers/media/usb/dvb-usb-v2/dvbsky.c | 25 +++++++++----------------
> 1 file changed, 9 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/media/usb/dvb-usb-v2/dvbsky.c
> b/drivers/media/usb/dvb-usb-v2/dvbsky.c index c41e10b..7d36f5f 100644
> --- a/drivers/media/usb/dvb-usb-v2/dvbsky.c

2019-11-08 19:18:03

by JP

Subject: Re: [PATCH 1/1] media: dvbsky: use a single mutex and state buffers for all R/W ops

On 11/8/19 7:22 PM, Brüns, Stefan wrote:
> On Freitag, 8. November 2019 19:15:13 CET Andrei Koshkosh wrote:
>> Signed-off-by: Andrei Koshkosh <[email protected]>
> Do not claim to be author of something you have not written.
>
> This is mostly commit 7d95fb746c4e "media: dvbsky: use just one mutex for
> serializing device R/W ops" originally from Mauro and later reverted.

See https://patchwork.linuxtv.org/patch/59590/
Apart from that,  this is allready in current linux_media tree.

Jan Pieter.