Re: [PATCH 1/3] usb: typec: tipd: add error message for vendor ID read failure

[Heikki Krogerus <heikki.krogerus@linux.intel.com>]

On Mon, May 18, 2026 at 09:23:58PM +0530, Pandey, Radhey Shyam wrote:
> On 5/18/2026 3:49 PM, Heikki Krogerus wrote:
> > On Wed, May 13, 2026 at 11:58:48PM +0530, Radhey Shyam Pandey wrote:
> > > Log when the vendor ID read fails or returns zero, including the I2C error
> > > code and register value, to ease probe diagnostics.
> > > 
> > > Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>
> > > ---
> > >   drivers/usb/typec/tipd/core.c | 7 +++++--
> > >   1 file changed, 5 insertions(+), 2 deletions(-)
> > > 
> > > diff --git a/drivers/usb/typec/tipd/core.c b/drivers/usb/typec/tipd/core.c
> > > index 43faec794b95..b282366b5326 100644
> > > --- a/drivers/usb/typec/tipd/core.c
> > > +++ b/drivers/usb/typec/tipd/core.c
> > > @@ -1744,7 +1744,7 @@ static int tps6598x_probe(struct i2c_client *client)
> > >   	struct tps6598x *tps;
> > >   	struct fwnode_handle *fwnode;
> > >   	u32 status;
> > > -	u32 vid;
> > > +	u32 vid = 0;
> > 
> > Why is this necessary?
> 
> Thanks for the review.
> 
> When ret < 0, tps6598x_read32() → tps6598x_block_read() returns on
> error before writing *val. So vid is never set; passing it to
> dev_err with %#x would read an uninitialized u32(random log noise).
> 
> ret captures if I2C/regmap path reported an error and vid tells what
> came back when the transport layer did not fail. Hope that clarifies.

Okay, got it.

Thanks,

> Thanks,
> Radhey
> > 
> > >   	int ret;
> > >   	data = i2c_get_match_data(client);
> > > @@ -1772,8 +1772,11 @@ static int tps6598x_probe(struct i2c_client *client)
> > >   	if (!device_is_compatible(tps->dev, "ti,tps25750")) {
> > >   		ret = tps6598x_read32(tps, TPS_REG_VID, &vid);
> > > -		if (ret < 0 || !vid)
> > > +		if (ret < 0 || !vid) {
> > > +			dev_err(tps->dev, "failed to read vendor ID: %d, vid: %#x\n",
> > > +				ret, vid);
> > >   			return -ENODEV;
> > > +		}
> > >   	}
> > >   	/*
> > > -- 
> > > 2.44.4
> > 

-- 
heikki