Re: [PATCH] drm: adv7511: override i2c address of cec before accessing it
Quoting Antonio Borneo (2021-12-20 15:53:12)
> On Mon, 2021-12-20 at 14:54 +, Kieran Bingham wrote:
> > Hi Antonio,
> >
> > Quoting Antonio Borneo (2021-12-18 18:28:04)
> > > Commit 680532c50bca ("drm: adv7511: Add support for
> > > i2c_new_secondary_device") allows a device tree node to override
> > > the default addresses of the secondary i2c devices. This is useful
> > > for solving address conflicts on the i2c bus.
> > >
> > > In adv7511_init_cec_regmap() the new i2c address of cec device is
> > > read from device tree and immediately accessed, well before it is
> > > written in the proper register to override the default address.
> > > This can cause an i2c error during probe and a consequent probe
> > > failure.
> >
> > Ouch, it does seem that way. I guess no one has used the CEC for
> > quite
> > some time, as it must have been like this for a while?
>
> Using the default i2c address for cec works without problem; apparently
> everyone is happy with such default. The issue appears only when you
> have to override the default cec address.
> The commit 680532c50bca landed in v4.18.
Ok, phew - so the 'normal' case still worked. That makes sense.
Sorry for getting it wrong, and I hope it didn't take too long to find
and fix. I'm sure we'll see it percolate down the stable trees once
integrated.
--
Kieran
> > > Once the new i2c address is read from the device tree, override
> > > the default address before any attempt to access the cec.
> >
> > Reviewed-by: Kieran Bingham
>
> Thanks!
> Antonio
>
> > > Tested with adv7533 and stm32mp157f.
> > >
> > > Signed-off-by: Antonio Borneo
> > > Fixes: 680532c50bca ("drm: adv7511: Add support for
> > > i2c_new_secondary_device")
> > > ---
> > > To: Andrzej Hajda
> > > To: Neil Armstrong
> > > To: Robert Foss
> > > To: Laurent Pinchart
> > > To: Jonas Karlman
> > > To: Jernej Skrabec
> > > To: David Airlie
> > > To: Daniel Vetter
> > > To: Kieran Bingham
> > > To: dri-devel@lists.freedesktop.org
> > > Cc: linux-ker...@vger.kernel.org
> > > Cc: linux-st...@st-md-mailman.stormreply.com
> > > ---
> > > drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 7 ---
> > > 1 file changed, 4 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> > > b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> > > index 76555ae64e9c..629e05286fd9 100644
> > > --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> > > +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> > > @@ -1048,6 +1048,10 @@ static int adv7511_init_cec_regmap(struct
> > > adv7511 *adv)
> > >
> > > ADV7511_CEC_I2C_ADDR_DEFAULT);
> > > if (IS_ERR(adv->i2c_cec))
> > > return PTR_ERR(adv->i2c_cec);
> > > +
> > > + regmap_write(adv->regmap, ADV7511_REG_CEC_I2C_ADDR,
> > > + adv->i2c_cec->addr << 1);
> > > +
> > > i2c_set_clientdata(adv->i2c_cec, adv);
> > >
> > > adv->regmap_cec = devm_regmap_init_i2c(adv->i2c_cec,
> > > @@ -1252,9 +1256,6 @@ static int adv7511_probe(struct i2c_client
> > > *i2c, const struct i2c_device_id *id)
> > > if (ret)
> > > goto err_i2c_unregister_packet;
> > >
> > > - regmap_write(adv7511->regmap, ADV7511_REG_CEC_I2C_ADDR,
> > > - adv7511->i2c_cec->addr << 1);
> > > -
> > > INIT_WORK(>hpd_work, adv7511_hpd_work);
> > >
> > > if (i2c->irq) {
> > >
> > > base-commit: fc74881c28d314b10efac016ef49df4ff40b8b97
> > > --
> > > 2.34.1
> > >
>
Re: [PATCH] drm: adv7511: override i2c address of cec before accessing it
On Mon, 2021-12-20 at 14:54 +, Kieran Bingham wrote:
> Hi Antonio,
>
> Quoting Antonio Borneo (2021-12-18 18:28:04)
> > Commit 680532c50bca ("drm: adv7511: Add support for
> > i2c_new_secondary_device") allows a device tree node to override
> > the default addresses of the secondary i2c devices. This is useful
> > for solving address conflicts on the i2c bus.
> >
> > In adv7511_init_cec_regmap() the new i2c address of cec device is
> > read from device tree and immediately accessed, well before it is
> > written in the proper register to override the default address.
> > This can cause an i2c error during probe and a consequent probe
> > failure.
>
> Ouch, it does seem that way. I guess no one has used the CEC for
> quite
> some time, as it must have been like this for a while?
Using the default i2c address for cec works without problem; apparently
everyone is happy with such default. The issue appears only when you
have to override the default cec address.
The commit 680532c50bca landed in v4.18.
> > Once the new i2c address is read from the device tree, override
> > the default address before any attempt to access the cec.
>
> Reviewed-by: Kieran Bingham
Thanks!
Antonio
> > Tested with adv7533 and stm32mp157f.
> >
> > Signed-off-by: Antonio Borneo
> > Fixes: 680532c50bca ("drm: adv7511: Add support for
> > i2c_new_secondary_device")
> > ---
> > To: Andrzej Hajda
> > To: Neil Armstrong
> > To: Robert Foss
> > To: Laurent Pinchart
> > To: Jonas Karlman
> > To: Jernej Skrabec
> > To: David Airlie
> > To: Daniel Vetter
> > To: Kieran Bingham
> > To: dri-devel@lists.freedesktop.org
> > Cc: linux-ker...@vger.kernel.org
> > Cc: linux-st...@st-md-mailman.stormreply.com
> > ---
> > drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 7 ---
> > 1 file changed, 4 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> > b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> > index 76555ae64e9c..629e05286fd9 100644
> > --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> > +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> > @@ -1048,6 +1048,10 @@ static int adv7511_init_cec_regmap(struct
> > adv7511 *adv)
> >
> > ADV7511_CEC_I2C_ADDR_DEFAULT);
> > if (IS_ERR(adv->i2c_cec))
> > return PTR_ERR(adv->i2c_cec);
> > +
> > + regmap_write(adv->regmap, ADV7511_REG_CEC_I2C_ADDR,
> > + adv->i2c_cec->addr << 1);
> > +
> > i2c_set_clientdata(adv->i2c_cec, adv);
> >
> > adv->regmap_cec = devm_regmap_init_i2c(adv->i2c_cec,
> > @@ -1252,9 +1256,6 @@ static int adv7511_probe(struct i2c_client
> > *i2c, const struct i2c_device_id *id)
> > if (ret)
> > goto err_i2c_unregister_packet;
> >
> > - regmap_write(adv7511->regmap, ADV7511_REG_CEC_I2C_ADDR,
> > - adv7511->i2c_cec->addr << 1);
> > -
> > INIT_WORK(>hpd_work, adv7511_hpd_work);
> >
> > if (i2c->irq) {
> >
> > base-commit: fc74881c28d314b10efac016ef49df4ff40b8b97
> > --
> > 2.34.1
> >
Re: [PATCH] drm: adv7511: override i2c address of cec before accessing it
Hi Antonio,
Quoting Antonio Borneo (2021-12-18 18:28:04)
> Commit 680532c50bca ("drm: adv7511: Add support for
> i2c_new_secondary_device") allows a device tree node to override
> the default addresses of the secondary i2c devices. This is useful
> for solving address conflicts on the i2c bus.
>
> In adv7511_init_cec_regmap() the new i2c address of cec device is
> read from device tree and immediately accessed, well before it is
> written in the proper register to override the default address.
> This can cause an i2c error during probe and a consequent probe
> failure.
Ouch, it does seem that way. I guess no one has used the CEC for quite
some time, as it must have been like this for a while?
> Once the new i2c address is read from the device tree, override
> the default address before any attempt to access the cec.
Reviewed-by: Kieran Bingham
> Tested with adv7533 and stm32mp157f.
>
> Signed-off-by: Antonio Borneo
> Fixes: 680532c50bca ("drm: adv7511: Add support for i2c_new_secondary_device")
> ---
> To: Andrzej Hajda
> To: Neil Armstrong
> To: Robert Foss
> To: Laurent Pinchart
> To: Jonas Karlman
> To: Jernej Skrabec
> To: David Airlie
> To: Daniel Vetter
> To: Kieran Bingham
> To: dri-devel@lists.freedesktop.org
> Cc: linux-ker...@vger.kernel.org
> Cc: linux-st...@st-md-mailman.stormreply.com
> ---
> drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 7 ---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> index 76555ae64e9c..629e05286fd9 100644
> --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> @@ -1048,6 +1048,10 @@ static int adv7511_init_cec_regmap(struct adv7511 *adv)
> ADV7511_CEC_I2C_ADDR_DEFAULT);
> if (IS_ERR(adv->i2c_cec))
> return PTR_ERR(adv->i2c_cec);
> +
> + regmap_write(adv->regmap, ADV7511_REG_CEC_I2C_ADDR,
> +adv->i2c_cec->addr << 1);
> +
> i2c_set_clientdata(adv->i2c_cec, adv);
>
> adv->regmap_cec = devm_regmap_init_i2c(adv->i2c_cec,
> @@ -1252,9 +1256,6 @@ static int adv7511_probe(struct i2c_client *i2c, const
> struct i2c_device_id *id)
> if (ret)
> goto err_i2c_unregister_packet;
>
> - regmap_write(adv7511->regmap, ADV7511_REG_CEC_I2C_ADDR,
> -adv7511->i2c_cec->addr << 1);
> -
> INIT_WORK(>hpd_work, adv7511_hpd_work);
>
> if (i2c->irq) {
>
> base-commit: fc74881c28d314b10efac016ef49df4ff40b8b97
> --
> 2.34.1
>
