linux/drivers/dma/dw
Serge Semin 0f9d5f008e dmaengine: dw: Initialize max_sg_burst capability
Multi-block support provides a way to map the kernel-specific SG-table so
the DW DMA device would handle it as a whole instead of handling the
SG-list items or so called LLP block items one by one. So if true LLP
list isn't supported by the DW DMA engine, then soft-LLP mode will be
utilized to load and execute each LLP-block one by one. The soft-LLP mode
of the DMA transactions execution might not work well for some DMA
consumers like SPI due to its Tx and Rx buffers inter-dependency. Let's
initialize the max_sg_burst DMA channels capability based on the nollp
flag state. If it's true, no hardware accelerated LLP is available and
max_sg_burst should be set with 1, which means that the DMA engine
can handle only a single SG list entry at a time. If noLLP is set to
false, then hardware accelerated LLP is supported and the DMA engine
can handle infinite number of SG entries in a single DMA transaction.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200723005848.31907-11-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2020-07-27 14:30:55 +05:30
..
acpi.c dmaengine: dw: Register ACPI DMA controller for PCI that has companion 2020-06-16 21:54:47 +05:30
core.c dmaengine: dw: Initialize max_sg_burst capability 2020-07-27 14:30:55 +05:30
dw.c dmaengine: dw: Don't pollute CTL_LO on iDMA 32-bit 2019-01-07 17:57:13 +05:30
idma32.c dmaengine: dw: Don't pollute CTL_LO on iDMA 32-bit 2019-01-07 17:57:13 +05:30
internal.h dmaengine: dw: platform: Split OF helpers to separate module 2019-08-21 09:41:28 +05:30
Kconfig dmaengine: dw: convert to SPDX identifiers 2019-01-07 17:57:13 +05:30
Makefile dmaengine: dw: Replace 'objs' by 'y' 2020-06-16 21:54:47 +05:30
of.c dmaengine: dw: Introduce max burst length hw config 2020-07-27 14:30:55 +05:30
pci.c dmaengine: dw: Register ACPI DMA controller for PCI that has companion 2020-06-16 21:54:47 +05:30
platform.c dmaengine: dw: platform: Mark 'hclk' clock optional 2019-10-14 13:51:44 +05:30
regs.h dmaengine: dw: Introduce max burst length hw config 2020-07-27 14:30:55 +05:30