From: Andy Shevchenko <andriy.shevchenko@intel.com>
To: Mark Brown <broonie@kernel.org>
Cc: "David Lechner" <dlechner@baylibre.com>,
"Rob Herring" <robh@kernel.org>,
"Krzysztof Kozlowski" <krzk+dt@kernel.org>,
"Conor Dooley" <conor+dt@kernel.org>,
"Marcelo Schmitt" <marcelo.schmitt@analog.com>,
"Michael Hennerich" <michael.hennerich@analog.com>,
"Nuno Sá" <nuno.sa@analog.com>,
"Jonathan Cameron" <jic23@kernel.org>,
"Andy Shevchenko" <andy@kernel.org>,
"Sean Anderson" <sean.anderson@linux.dev>,
linux-spi@vger.kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org
Subject: Re: [PATCH v5 3/9] spi: support controllers with multiple data lanes
Date: Mon, 12 Jan 2026 21:35:32 +0200 [thread overview]
Message-ID: <aWVNBPfv-R5erugo@smile.fi.intel.com> (raw)
In-Reply-To: <22a6a28c-0f03-4571-b2a0-8c9b82788b68@sirena.org.uk>
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
next prev parent reply other threads:[~2026-01-12 19:35 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-12 17:45 [PATCH v5 0/9] spi: add multi-lane support David Lechner
2026-01-12 17:45 ` [PATCH v5 1/9] spi: dt-bindings: change spi-{rx,tx}-bus-width to arrays David Lechner
2026-01-12 17:45 ` [PATCH v5 2/9] spi: dt-bindings: add spi-{tx,rx}-lane-map properties David Lechner
2026-01-14 8:57 ` Jonathan Cameron
2026-01-12 17:45 ` [PATCH v5 3/9] spi: support controllers with multiple data lanes David Lechner
2026-01-12 19:07 ` Andy Shevchenko
2026-01-12 19:11 ` Mark Brown
2026-01-12 19:35 ` Andy Shevchenko [this message]
2026-01-16 23:12 ` David Lechner
2026-01-19 7:44 ` Andy Shevchenko
2026-01-14 9:05 ` Jonathan Cameron
2026-01-16 22:20 ` David Lechner
2026-01-12 17:45 ` [PATCH v5 4/9] spi: add multi_lane_mode field to struct spi_transfer David Lechner
2026-01-14 9:06 ` Jonathan Cameron
2026-01-12 17:45 ` [PATCH v5 5/9] spi: Documentation: add page on multi-lane support David Lechner
2026-01-14 9:10 ` Jonathan Cameron
2026-01-16 22:35 ` David Lechner
2026-01-19 10:11 ` Jonathan Cameron
2026-01-23 20:00 ` David Lechner
2026-01-12 17:45 ` [PATCH v5 6/9] spi: dt-bindings: adi,axi-spi-engine: add " David Lechner
2026-01-14 9:11 ` Jonathan Cameron
2026-01-12 17:45 ` [PATCH v5 7/9] spi: axi-spi-engine: support SPI_MULTI_LANE_MODE_STRIPE David Lechner
2026-01-14 9:16 ` Jonathan Cameron
2026-01-16 22:43 ` David Lechner
2026-01-12 17:45 ` [PATCH v5 8/9] dt-bindings: iio: adc: adi,ad7380: add spi-rx-bus-width property David Lechner
2026-01-12 17:45 ` [PATCH v5 9/9] iio: adc: ad7380: add support for multiple SPI lanes David Lechner
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