> On Tue, Mar 26, 2019 at 10:56:39PM -0700, Sowjanya Komatineni wrote:
> 
> > Tegra SPI driver default uses SW CS control for transfers and HW CS 
> > control can be enabled through SPI client device node DT property 
> > nvidia,enable-hw-based-cs and is used only for single transfers.
>
> Why have a property - if this feature works and is useful why would a system 
> ever not want to use it?

> > +   single_xfer = list_is_singular(&msg->transfers);
> >     list_for_each_entry(xfer, &msg->transfers, transfer_list) {
> >             u32 cmd1;
> >  
> >             reinit_completion(&tspi->xfer_completion);
> >  
> > -           cmd1 = tegra_spi_setup_transfer_one(spi, xfer, is_first_msg);
> > +           cmd1 = tegra_spi_setup_transfer_one(spi, xfer, is_first_msg,
> > +                                               single_xfer);
>
> It's not sufficient to check if there's only one transfer, you also need to 
> make sure that the driver isn't using cs_change to use non-standard chip 
> select handling.

Yes we can avoid DT and force to use HW CS incase of all single transfers 
without cs_change. Will update in next version.

Reply via email to