On Wed, Apr 13, 2022 at 03:32:50PM +0530, Aswath Govindraju wrote: > Hi Heikki, > > On 13/04/22 15:04, Heikki Krogerus wrote: > > Hi Aswath, > > > > On Tue, Apr 12, 2022 at 08:20:58PM +0530, Aswath Govindraju wrote: > >> In some cases the interrupt line from the pd controller may not be > >> connected. In these cases, poll the status of various events. > > > > Well, if the alert/interrupt line is not connected anywhere, then > > polling is the only way to go. I'm fine with that, but the driver > > really should be told that there is no interrupt. Using polling > > whenever request_threaded_irq() returns -EINVAL is wrong. We really > > should not even attempt to request the interrupt if there is no > > interrupt for the device. > > > > Isn't there any way you can get that information from DT? Or how is > > the device enumerated in your case? > > > > Would checking if (client->irq) field is populated, to decide between > polling and interrupts be a good approach? > > I am sorry but I did not understand what you meant by device getting > enumerated. The device is on an I2C bus and gets enumerated based on the > I2C address provided. The device does not have I2C_IRQ line connected, > in my case. "I2C devices are not enumerated at hardware level": https://www.kernel.org/doc/html/latest/i2c/instantiating-devices.html So your PD controller I2C slave device has to be either described in Devicetree or ACPI tables, or there is a board file or platform driver that actually populates the device for it. Can you tell a little bit about the platform you are running? Is it ARM, x86, or what, and is it ACPI or DT platform? thanks, -- heikki
