Re: [PATCH v2 5/5] media: mt9p031: Fix corrupted frame after restarting stream
Hi Laurent, On 05.10.20 15:08, Laurent Pinchart wrote: Hi Stefan, On Mon, Oct 05, 2020 at 11:28:21AM +0200, Stefan Riedmüller wrote: On 02.10.20 02:05, Laurent Pinchart wrote: On Wed, Sep 30, 2020 at 12:51:33PM +0200, Stefan Riedmueller wrote: From: Dirk Bender To prevent corrupted frames after starting and stopping the sensor it's s/it's/its/ thanks, I'll fix that. datasheet specifies a specific pause sequence to follow: Stopping: Set Pause_Restart Bit -> Set Restart Bit -> Set Chip_Enable Off Restarting: Set Chip_Enable On -> Clear Pause_Restart Bit The Restart Bit is cleared automatically and must not be cleared manually as this would cause undefined behavior. Signed-off-by: Dirk Bender Signed-off-by: Stefan Riedmueller --- No changes in v2 --- drivers/media/i2c/mt9p031.c | 25 + 1 file changed, 25 insertions(+) diff --git a/drivers/media/i2c/mt9p031.c b/drivers/media/i2c/mt9p031.c index d10457361e6c..d59f66e3dcf3 100644 --- a/drivers/media/i2c/mt9p031.c +++ b/drivers/media/i2c/mt9p031.c @@ -80,6 +80,8 @@ #define MT9P031_PIXEL_CLOCK_SHIFT(n)((n) << 8) #define MT9P031_PIXEL_CLOCK_DIVIDE(n) ((n) << 0) #define MT9P031_FRAME_RESTART0x0b +#defineMT9P031_FRAME_RESTART_SET (1 << 0) +#defineMT9P031_FRAME_PAUSE_RESTART_SET (1 << 1) The fields are named Restart and Pause_Restart, I would drop _SET. Could you also sort them from MSB to LSB as for the other registers ? Using BIT() would be good too, although this could be done as an additional patch to convert all the existing macros. I'll do that. Also I will rename the register to MT9P031_RESTART and the bits to MT9P031_FRAME_RESTART and MT9P031_FRAME_PAUSE_RESTART. #define MT9P031_SHUTTER_DELAY0x0c #define MT9P031_RST 0x0d #define MT9P031_RST_ENABLE 1 @@ -483,9 +485,25 @@ static int mt9p031_set_params(struct mt9p031 *mt9p031) static int mt9p031_s_stream(struct v4l2_subdev *subdev, int enable) { struct mt9p031 *mt9p031 = to_mt9p031(subdev); + struct i2c_client *client = v4l2_get_subdevdata(subdev); + int val; int ret; if (!enable) { + val = mt9p031_read(client, MT9P031_FRAME_RESTART); Do you need to read the register ? Can't you write MT9P031_FRAME_PAUSE_RESTART_SET and then MT9P031_FRAME_PAUSE_RESTART_SET | MT9P031_FRAME_RESTART_SET ? And actually, can't we just write both bits in one go, do we need two writes ? I think you're right we don't necessarily need to read the registers. The only other bit is not used by the driver. But I think we do need two separate writes, at least that is what the datasheet states. So I would drop the read but keep both write, ok? That's fine with me if required, although I don't see where this is indicated in the datasheet, but I may have missed it. It's in "Standby and Chip Enable". There is a Sequence for entering soft standby with two separate writes: REG = 0x0B, 0x0002 REG = 0x0B, 0x0003 Regards, Stefan + + /* enable pause restart */ + val |= MT9P031_FRAME_PAUSE_RESTART_SET; + ret = mt9p031_write(client, MT9P031_FRAME_RESTART, val); + if (ret < 0) + return ret; + + /* enable restart + keep pause restart set */ + val |= MT9P031_FRAME_RESTART_SET; + ret = mt9p031_write(client, MT9P031_FRAME_RESTART, val); + if (ret < 0) + return ret; + /* Stop sensor readout */ ret = mt9p031_set_output_control(mt9p031, MT9P031_OUTPUT_CONTROL_CEN, 0); @@ -505,6 +523,13 @@ static int mt9p031_s_stream(struct v4l2_subdev *subdev, int enable) if (ret < 0) return ret; + val = mt9p031_read(client, MT9P031_FRAME_RESTART); + /* disable reset + pause restart */ + val &= ~MT9P031_FRAME_PAUSE_RESTART_SET; Same here, I think you can simply write MT9P031_FRAME_PAUSE_RESTART_SET. I'll drop the read here as well. But I need to make sure, that the Restart Bit is not cleared manually here. + ret = mt9p031_write(client, MT9P031_FRAME_RESTART, val); + if (ret < 0) + return ret; + return mt9p031_pll_enable(mt9p031); }
Re: [PATCH v2 5/5] media: mt9p031: Fix corrupted frame after restarting stream
Hi Stefan, On Mon, Oct 05, 2020 at 11:28:21AM +0200, Stefan Riedmüller wrote: > On 02.10.20 02:05, Laurent Pinchart wrote: > > On Wed, Sep 30, 2020 at 12:51:33PM +0200, Stefan Riedmueller wrote: > >> From: Dirk Bender > >> > >> To prevent corrupted frames after starting and stopping the sensor it's > > > > s/it's/its/ > > thanks, I'll fix that. > > >> datasheet specifies a specific pause sequence to follow: > >> > >> Stopping: > >>Set Pause_Restart Bit -> Set Restart Bit -> Set Chip_Enable Off > >> > >> Restarting: > >>Set Chip_Enable On -> Clear Pause_Restart Bit > >> > >> The Restart Bit is cleared automatically and must not be cleared > >> manually as this would cause undefined behavior. > >> > >> Signed-off-by: Dirk Bender > >> Signed-off-by: Stefan Riedmueller > >> --- > >> No changes in v2 > >> --- > >> drivers/media/i2c/mt9p031.c | 25 + > >> 1 file changed, 25 insertions(+) > >> > >> diff --git a/drivers/media/i2c/mt9p031.c b/drivers/media/i2c/mt9p031.c > >> index d10457361e6c..d59f66e3dcf3 100644 > >> --- a/drivers/media/i2c/mt9p031.c > >> +++ b/drivers/media/i2c/mt9p031.c > >> @@ -80,6 +80,8 @@ > >> #define MT9P031_PIXEL_CLOCK_SHIFT(n)((n) << 8) > >> #define MT9P031_PIXEL_CLOCK_DIVIDE(n) ((n) << 0) > >> #define MT9P031_FRAME_RESTART0x0b > >> +#define MT9P031_FRAME_RESTART_SET (1 << 0) > >> +#define MT9P031_FRAME_PAUSE_RESTART_SET (1 << 1) > > > > The fields are named Restart and Pause_Restart, I would drop _SET. Could > > you also sort them from MSB to LSB as for the other registers ? Using > > BIT() would be good too, although this could be done as an additional > > patch to convert all the existing macros. > > I'll do that. Also I will rename the register to MT9P031_RESTART and the > bits to MT9P031_FRAME_RESTART and MT9P031_FRAME_PAUSE_RESTART. > > >> #define MT9P031_SHUTTER_DELAY0x0c > >> #define MT9P031_RST 0x0d > >> #define MT9P031_RST_ENABLE 1 > >> @@ -483,9 +485,25 @@ static int mt9p031_set_params(struct mt9p031 *mt9p031) > >> static int mt9p031_s_stream(struct v4l2_subdev *subdev, int enable) > >> { > >>struct mt9p031 *mt9p031 = to_mt9p031(subdev); > >> + struct i2c_client *client = v4l2_get_subdevdata(subdev); > >> + int val; > >>int ret; > >> > >>if (!enable) { > >> + val = mt9p031_read(client, MT9P031_FRAME_RESTART); > > > > Do you need to read the register ? Can't you write > > MT9P031_FRAME_PAUSE_RESTART_SET and then MT9P031_FRAME_PAUSE_RESTART_SET > > | MT9P031_FRAME_RESTART_SET ? And actually, can't we just write both > > bits in one go, do we need two writes ? > > I think you're right we don't necessarily need to read the registers. The > only other bit is not used by the driver. > > But I think we do need two separate writes, at least that is what the > datasheet states. > > So I would drop the read but keep both write, ok? That's fine with me if required, although I don't see where this is indicated in the datasheet, but I may have missed it. > >> + > >> + /* enable pause restart */ > >> + val |= MT9P031_FRAME_PAUSE_RESTART_SET; > >> + ret = mt9p031_write(client, MT9P031_FRAME_RESTART, val); > >> + if (ret < 0) > >> + return ret; > >> + > >> + /* enable restart + keep pause restart set */ > >> + val |= MT9P031_FRAME_RESTART_SET; > >> + ret = mt9p031_write(client, MT9P031_FRAME_RESTART, val); > >> + if (ret < 0) > >> + return ret; > >> + > >>/* Stop sensor readout */ > >>ret = mt9p031_set_output_control(mt9p031, > >> MT9P031_OUTPUT_CONTROL_CEN, 0); > >> @@ -505,6 +523,13 @@ static int mt9p031_s_stream(struct v4l2_subdev > >> *subdev, int enable) > >>if (ret < 0) > >>return ret; > >> > >> + val = mt9p031_read(client, MT9P031_FRAME_RESTART); > >> + /* disable reset + pause restart */ > >> + val &= ~MT9P031_FRAME_PAUSE_RESTART_SET; > > > > Same here, I think you can simply write MT9P031_FRAME_PAUSE_RESTART_SET. > > I'll drop the read here as well. But I need to make sure, that the Restart > Bit is not cleared manually here. > > >> + ret = mt9p031_write(client, MT9P031_FRAME_RESTART, val); > >> + if (ret < 0) > >> + return ret; > >> + > >>return mt9p031_pll_enable(mt9p031); > >> } > >> -- Regards, Laurent Pinchart
Re: [PATCH v2 5/5] media: mt9p031: Fix corrupted frame after restarting stream
Hi Laurent, On 02.10.20 02:05, Laurent Pinchart wrote: Hi Stefan, Thank you for the patch. On Wed, Sep 30, 2020 at 12:51:33PM +0200, Stefan Riedmueller wrote: From: Dirk Bender To prevent corrupted frames after starting and stopping the sensor it's s/it's/its/ thanks, I'll fix that. datasheet specifies a specific pause sequence to follow: Stopping: Set Pause_Restart Bit -> Set Restart Bit -> Set Chip_Enable Off Restarting: Set Chip_Enable On -> Clear Pause_Restart Bit The Restart Bit is cleared automatically and must not be cleared manually as this would cause undefined behavior. Signed-off-by: Dirk Bender Signed-off-by: Stefan Riedmueller --- No changes in v2 --- drivers/media/i2c/mt9p031.c | 25 + 1 file changed, 25 insertions(+) diff --git a/drivers/media/i2c/mt9p031.c b/drivers/media/i2c/mt9p031.c index d10457361e6c..d59f66e3dcf3 100644 --- a/drivers/media/i2c/mt9p031.c +++ b/drivers/media/i2c/mt9p031.c @@ -80,6 +80,8 @@ #define MT9P031_PIXEL_CLOCK_SHIFT(n)((n) << 8) #define MT9P031_PIXEL_CLOCK_DIVIDE(n) ((n) << 0) #define MT9P031_FRAME_RESTART 0x0b +#defineMT9P031_FRAME_RESTART_SET (1 << 0) +#defineMT9P031_FRAME_PAUSE_RESTART_SET (1 << 1) The fields are named Restart and Pause_Restart, I would drop _SET. Could you also sort them from MSB to LSB as for the other registers ? Using BIT() would be good too, although this could be done as an additional patch to convert all the existing macros. I'll do that. Also I will rename the register to MT9P031_RESTART and the bits to MT9P031_FRAME_RESTART and MT9P031_FRAME_PAUSE_RESTART. #define MT9P031_SHUTTER_DELAY 0x0c #define MT9P031_RST 0x0d #define MT9P031_RST_ENABLE 1 @@ -483,9 +485,25 @@ static int mt9p031_set_params(struct mt9p031 *mt9p031) static int mt9p031_s_stream(struct v4l2_subdev *subdev, int enable) { struct mt9p031 *mt9p031 = to_mt9p031(subdev); + struct i2c_client *client = v4l2_get_subdevdata(subdev); + int val; int ret; if (!enable) { + val = mt9p031_read(client, MT9P031_FRAME_RESTART); Do you need to read the register ? Can't you write MT9P031_FRAME_PAUSE_RESTART_SET and then MT9P031_FRAME_PAUSE_RESTART_SET | MT9P031_FRAME_RESTART_SET ? And actually, can't we just write both bits in one go, do we need two writes ? I think you're right we don't necessarily need to read the registers. The only other bit is not used by the driver. But I think we do need two separate writes, at least that is what the datasheet states. So I would drop the read but keep both write, ok? + + /* enable pause restart */ + val |= MT9P031_FRAME_PAUSE_RESTART_SET; + ret = mt9p031_write(client, MT9P031_FRAME_RESTART, val); + if (ret < 0) + return ret; + + /* enable restart + keep pause restart set */ + val |= MT9P031_FRAME_RESTART_SET; + ret = mt9p031_write(client, MT9P031_FRAME_RESTART, val); + if (ret < 0) + return ret; + /* Stop sensor readout */ ret = mt9p031_set_output_control(mt9p031, MT9P031_OUTPUT_CONTROL_CEN, 0); @@ -505,6 +523,13 @@ static int mt9p031_s_stream(struct v4l2_subdev *subdev, int enable) if (ret < 0) return ret; + val = mt9p031_read(client, MT9P031_FRAME_RESTART); + /* disable reset + pause restart */ + val &= ~MT9P031_FRAME_PAUSE_RESTART_SET; Same here, I think you can simply write MT9P031_FRAME_PAUSE_RESTART_SET. I'll drop the read here as well. But I need to make sure, that the Restart Bit is not cleared manually here. Regards, Stefan + ret = mt9p031_write(client, MT9P031_FRAME_RESTART, val); + if (ret < 0) + return ret; + return mt9p031_pll_enable(mt9p031); }
Re: [PATCH v2 5/5] media: mt9p031: Fix corrupted frame after restarting stream
Hi Stefan, Thank you for the patch. On Wed, Sep 30, 2020 at 12:51:33PM +0200, Stefan Riedmueller wrote: > From: Dirk Bender > > To prevent corrupted frames after starting and stopping the sensor it's s/it's/its/ > datasheet specifies a specific pause sequence to follow: > > Stopping: > Set Pause_Restart Bit -> Set Restart Bit -> Set Chip_Enable Off > > Restarting: > Set Chip_Enable On -> Clear Pause_Restart Bit > > The Restart Bit is cleared automatically and must not be cleared > manually as this would cause undefined behavior. > > Signed-off-by: Dirk Bender > Signed-off-by: Stefan Riedmueller > --- > No changes in v2 > --- > drivers/media/i2c/mt9p031.c | 25 + > 1 file changed, 25 insertions(+) > > diff --git a/drivers/media/i2c/mt9p031.c b/drivers/media/i2c/mt9p031.c > index d10457361e6c..d59f66e3dcf3 100644 > --- a/drivers/media/i2c/mt9p031.c > +++ b/drivers/media/i2c/mt9p031.c > @@ -80,6 +80,8 @@ > #define MT9P031_PIXEL_CLOCK_SHIFT(n)((n) << 8) > #define MT9P031_PIXEL_CLOCK_DIVIDE(n) ((n) << 0) > #define MT9P031_FRAME_RESTART0x0b > +#define MT9P031_FRAME_RESTART_SET (1 << 0) > +#define MT9P031_FRAME_PAUSE_RESTART_SET (1 << 1) The fields are named Restart and Pause_Restart, I would drop _SET. Could you also sort them from MSB to LSB as for the other registers ? Using BIT() would be good too, although this could be done as an additional patch to convert all the existing macros. > #define MT9P031_SHUTTER_DELAY0x0c > #define MT9P031_RST 0x0d > #define MT9P031_RST_ENABLE 1 > @@ -483,9 +485,25 @@ static int mt9p031_set_params(struct mt9p031 *mt9p031) > static int mt9p031_s_stream(struct v4l2_subdev *subdev, int enable) > { > struct mt9p031 *mt9p031 = to_mt9p031(subdev); > + struct i2c_client *client = v4l2_get_subdevdata(subdev); > + int val; > int ret; > > if (!enable) { > + val = mt9p031_read(client, MT9P031_FRAME_RESTART); Do you need to read the register ? Can't you write MT9P031_FRAME_PAUSE_RESTART_SET and then MT9P031_FRAME_PAUSE_RESTART_SET | MT9P031_FRAME_RESTART_SET ? And actually, can't we just write both bits in one go, do we need two writes ? > + > + /* enable pause restart */ > + val |= MT9P031_FRAME_PAUSE_RESTART_SET; > + ret = mt9p031_write(client, MT9P031_FRAME_RESTART, val); > + if (ret < 0) > + return ret; > + > + /* enable restart + keep pause restart set */ > + val |= MT9P031_FRAME_RESTART_SET; > + ret = mt9p031_write(client, MT9P031_FRAME_RESTART, val); > + if (ret < 0) > + return ret; > + > /* Stop sensor readout */ > ret = mt9p031_set_output_control(mt9p031, >MT9P031_OUTPUT_CONTROL_CEN, 0); > @@ -505,6 +523,13 @@ static int mt9p031_s_stream(struct v4l2_subdev *subdev, > int enable) > if (ret < 0) > return ret; > > + val = mt9p031_read(client, MT9P031_FRAME_RESTART); > + /* disable reset + pause restart */ > + val &= ~MT9P031_FRAME_PAUSE_RESTART_SET; Same here, I think you can simply write MT9P031_FRAME_PAUSE_RESTART_SET. > + ret = mt9p031_write(client, MT9P031_FRAME_RESTART, val); > + if (ret < 0) > + return ret; > + > return mt9p031_pll_enable(mt9p031); > } > -- Regards, Laurent Pinchart
[PATCH v2 5/5] media: mt9p031: Fix corrupted frame after restarting stream
From: Dirk Bender To prevent corrupted frames after starting and stopping the sensor it's datasheet specifies a specific pause sequence to follow: Stopping: Set Pause_Restart Bit -> Set Restart Bit -> Set Chip_Enable Off Restarting: Set Chip_Enable On -> Clear Pause_Restart Bit The Restart Bit is cleared automatically and must not be cleared manually as this would cause undefined behavior. Signed-off-by: Dirk Bender Signed-off-by: Stefan Riedmueller --- No changes in v2 --- drivers/media/i2c/mt9p031.c | 25 + 1 file changed, 25 insertions(+) diff --git a/drivers/media/i2c/mt9p031.c b/drivers/media/i2c/mt9p031.c index d10457361e6c..d59f66e3dcf3 100644 --- a/drivers/media/i2c/mt9p031.c +++ b/drivers/media/i2c/mt9p031.c @@ -80,6 +80,8 @@ #defineMT9P031_PIXEL_CLOCK_SHIFT(n)((n) << 8) #defineMT9P031_PIXEL_CLOCK_DIVIDE(n) ((n) << 0) #define MT9P031_FRAME_RESTART 0x0b +#defineMT9P031_FRAME_RESTART_SET (1 << 0) +#defineMT9P031_FRAME_PAUSE_RESTART_SET (1 << 1) #define MT9P031_SHUTTER_DELAY 0x0c #define MT9P031_RST0x0d #defineMT9P031_RST_ENABLE 1 @@ -483,9 +485,25 @@ static int mt9p031_set_params(struct mt9p031 *mt9p031) static int mt9p031_s_stream(struct v4l2_subdev *subdev, int enable) { struct mt9p031 *mt9p031 = to_mt9p031(subdev); + struct i2c_client *client = v4l2_get_subdevdata(subdev); + int val; int ret; if (!enable) { + val = mt9p031_read(client, MT9P031_FRAME_RESTART); + + /* enable pause restart */ + val |= MT9P031_FRAME_PAUSE_RESTART_SET; + ret = mt9p031_write(client, MT9P031_FRAME_RESTART, val); + if (ret < 0) + return ret; + + /* enable restart + keep pause restart set */ + val |= MT9P031_FRAME_RESTART_SET; + ret = mt9p031_write(client, MT9P031_FRAME_RESTART, val); + if (ret < 0) + return ret; + /* Stop sensor readout */ ret = mt9p031_set_output_control(mt9p031, MT9P031_OUTPUT_CONTROL_CEN, 0); @@ -505,6 +523,13 @@ static int mt9p031_s_stream(struct v4l2_subdev *subdev, int enable) if (ret < 0) return ret; + val = mt9p031_read(client, MT9P031_FRAME_RESTART); + /* disable reset + pause restart */ + val &= ~MT9P031_FRAME_PAUSE_RESTART_SET; + ret = mt9p031_write(client, MT9P031_FRAME_RESTART, val); + if (ret < 0) + return ret; + return mt9p031_pll_enable(mt9p031); } -- 2.25.1