| Date | Mon, 1 Apr 2019 14:48:57 +0700 | From | Mark Brown <> | Subject | Re: [PATCH V1 18/26] spi: tegra114: add support for hw based cs |
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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. [unhandled content-type:application/pgp-signature] |