Quoting Antonio Borneo (2021-12-20 15:53:12) > On Mon, 2021-12-20 at 14:54 +0000, 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 <kieran.bingham+renesas@xxxxxxxxxxxxxxxx> > > Thanks! > Antonio > > > > Tested with adv7533 and stm32mp157f. > > > > > > Signed-off-by: Antonio Borneo <antonio.borneo@xxxxxxxxxxx> > > > Fixes: 680532c50bca ("drm: adv7511: Add support for > > > i2c_new_secondary_device") > > > --- > > > To: Andrzej Hajda <a.hajda@xxxxxxxxxxx> > > > To: Neil Armstrong <narmstrong@xxxxxxxxxxxx> > > > To: Robert Foss <robert.foss@xxxxxxxxxx> > > > To: Laurent Pinchart <Laurent.pinchart@xxxxxxxxxxxxxxxx> > > > To: Jonas Karlman <jonas@xxxxxxxxx> > > > To: Jernej Skrabec <jernej.skrabec@xxxxxxxxx> > > > To: David Airlie <airlied@xxxxxxxx> > > > To: Daniel Vetter <daniel@xxxxxxxx> > > > To: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx> > > > To: dri-devel@xxxxxxxxxxxxxxxxxxxxx > > > Cc: linux-kernel@xxxxxxxxxxxxxxx > > > Cc: linux-stm32@xxxxxxxxxxxxxxxxxxxxxxxxxxxx > > > --- > > > 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(&adv7511->hpd_work, adv7511_hpd_work); > > > > > > if (i2c->irq) { > > > > > > base-commit: fc74881c28d314b10efac016ef49df4ff40b8b97 > > > -- > > > 2.34.1 > > > >