Hi Wolfram, Do you have any comments on these patches? Thanks Ajay > nvpublic > -----Original Message----- > From: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> > Sent: Monday, October 29, 2018 5:43 AM > To: Ajay Gupta <ajayg@xxxxxxxxxx> > Cc: wsa@xxxxxxxxxxxxx; heikki.krogerus@xxxxxxxxxxxxxxx; peda@xxxxxxxxxx; > linux-usb@xxxxxxxxxxxxxxx; linux-i2c@xxxxxxxxxxxxxxx > Subject: Re: [PATCH v15 0/2] Add support for USB Type-C interface on latest > NVIDIA GPU > > On Fri, Oct 26, 2018 at 09:36:57AM -0700, Ajay Gupta wrote: > > Hi Heikki and Wolfram, > > > > These two changes add support for USB Type-C interface on latest NVIDIA > GPU card. > > The Type-C controller used is Cypress CCGx and is over I2C interface. > > > > I2C host controller has known limitation of sending STOP after every > > read. Since each read can be of 4 byte maximum length so there is a limit of > 4 byte read. > > This is mentioned in adapter quirks as "max_read_len = 4" > > > > I2C host controller is mainly used for "write-then-read" or "write" > > messages so added the flag I2C_AQ_COMB_WRITE_THEN_READ in adapter > quirks. > > > > PATCH[2/2] on ucsi driver now have added logic to check i2c adapter > > quirks and issues i2c read transfer based on max_read_len quirk > > settings. This will make sure the read limitation is not affecting I2C host > which do not have such limitation. > > > > I think the patches should through usb tree because the main > > functionality is usb Type-C. > > FWIW, > Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> > > > > > Thanks > > Ajay > > > > Ajay Gupta (2): > > i2c: buses: add i2c bus driver for NVIDIA GPU > > usb: typec: ucsi: add support for Cypress CCGx > > > > Documentation/i2c/busses/i2c-nvidia-gpu | 18 ++ > > MAINTAINERS | 7 + > > drivers/i2c/busses/Kconfig | 9 + > > drivers/i2c/busses/Makefile | 1 + > > drivers/i2c/busses/i2c-nvidia-gpu.c | 368 ++++++++++++++++++++++++ > > drivers/usb/typec/ucsi/Kconfig | 10 + > > drivers/usb/typec/ucsi/Makefile | 2 + > > drivers/usb/typec/ucsi/ucsi_ccg.c | 307 ++++++++++++++++++++ > > 8 files changed, 722 insertions(+) > > create mode 100644 Documentation/i2c/busses/i2c-nvidia-gpu > > create mode 100644 drivers/i2c/busses/i2c-nvidia-gpu.c > > create mode 100644 drivers/usb/typec/ucsi/ucsi_ccg.c > > > > -- > > 2.17.1 > > > > -- > With Best Regards, > Andy Shevchenko >
