Re: [PATCH v5 3/9] spi: support controllers with multiple data lanes

Andy Shevchenko
2026-01-12T19:35:37Z

On Mon, Jan 12, 2026 at 07:11:26PM +0000, Mark Brown wrote:
> On Mon, Jan 12, 2026 at 09:07:17PM +0200, Andy Shevchenko wrote:
> > On Mon, Jan 12, 2026 at 11:45:21AM -0600, David Lechner wrote:

...

> > > + /* Multi-lane SPI controller support. */
> > > + u32 tx_lane_map[SPI_DEVICE_DATA_LANE_CNT_MAX];
> > > + u32 num_tx_lanes;
> > > + u32 rx_lane_map[SPI_DEVICE_DATA_LANE_CNT_MAX];
> > > + u32 num_rx_lanes;
>
> > This adds 72 bytes in _each_ instance of spi_device on the platforms that do
> > not use the feature and might not ever use it. Can we move to the pointer
> > and allocate the mentioned fields separately, please?
>
> Do we have real systems where we have enough SPI devices for anyone to
> care?

Define "enough" :-) To me even dozen of devices is enough (it gets almost a 1kB
of space) esp. if we are talking about quite low profile embedded systems.

--
With Best Regards,
Andy Shevchenko