Meghana Madhyastha 8b7bd10eb0
spi/spi-bcm2835: Split transfers that exceed DLEN
Split spi transfers into chunks of <=65532 to enable the driver to
perform DMA transfer on big buffers. The DLEN register specifies the
number of bytes to transfer in DMA mode. It is 16-bit wide and thus the
maximum DMA transfer is 65535 bytes. Set the maximum to 65532 (4 byte
aligned) since the FIFO in DMA mode is accessed in 4 byte chunks.

->max_dma_len is the value the spi core uses when splitting the buffer
into scatter gather entries.
The BCM2835 DMA block has 2 types of channels/engines:
- Normal: Max length: 1G
- Lite: Max length: 65535

Even when using a Lite channel we will not exceed the max length, so
let's drop setting ->max_dma_len.

Signed-off-by: Meghana Madhyastha <meghana.madhyastha@gmail.com>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-05-02 10:37:55 +09:00
..
2019-03-16 13:05:32 -07:00
2019-03-09 16:53:47 -08:00
2019-03-16 13:05:32 -07:00
2019-03-16 12:36:39 -07:00
2019-03-06 09:41:12 -08:00
2019-03-16 13:05:32 -07:00
2019-03-14 09:11:54 -07:00
2019-03-09 14:57:08 -08:00
2019-03-06 14:18:59 -08:00
2019-03-15 14:37:46 -07:00
2019-03-08 10:02:58 -08:00
2019-03-11 20:06:18 -07:00
2019-03-15 14:41:30 -07:00
2019-03-10 10:17:23 -07:00
2019-03-10 13:16:37 -07:00
2019-03-07 08:59:26 -07:00
2019-03-16 12:36:39 -07:00
2019-03-10 11:54:48 -07:00
2019-03-10 11:54:48 -07:00
2019-03-09 15:53:03 -08:00
2019-03-08 14:12:17 -08:00
2019-03-16 13:05:32 -07:00
2019-03-16 12:36:39 -07:00
2019-03-10 11:54:48 -07:00
2019-03-10 12:29:52 -07:00
2019-03-10 10:17:23 -07:00
2019-03-08 08:23:15 -08:00
2019-03-12 09:46:32 -07:00
2019-03-14 09:00:06 -07:00
2019-03-12 09:46:32 -07:00
2019-03-16 12:51:50 -07:00
2019-03-06 09:41:12 -08:00
2019-03-16 12:51:50 -07:00
2019-03-06 09:41:12 -08:00
2019-03-14 09:11:54 -07:00
2019-03-07 12:56:26 -08:00
2019-03-10 12:47:57 -07:00
2019-03-15 14:22:59 -07:00
2019-03-11 11:22:15 -07:00
2019-03-10 12:29:52 -07:00