From 4498c31adff99d243b34b0bf39363a35ea070928 Mon Sep 17 00:00:00 2001 From: Alexandre Bounine Date: Tue, 2 Aug 2016 14:06:37 -0700 Subject: rapidio/tsi721_dma: add channel mask and queue size parameters Add module parameters to allow load time configuration of DMA channels. Depending on application, performance of DMA data transfers can benefit from adjusted sizes of buffer descriptor ring and/or transaction requests queue. Having HW DMA channel selector mask allows to define which channels (from seven available) are controlled by the mport device driver and reserve some of them for direct use by other drivers. Link: http://lkml.kernel.org/r/1469125134-16523-5-git-send-email-alexandre.bounine@idt.com Signed-off-by: Alexandre Bounine Tested-by: Barry Wood Cc: Matt Porter Cc: Andre van Herk Cc: Barry Wood Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/rapidio/tsi721.txt | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'Documentation/rapidio') diff --git a/Documentation/rapidio/tsi721.txt b/Documentation/rapidio/tsi721.txt index 7c1c7bf48ec0..0e0e90bef882 100644 --- a/Documentation/rapidio/tsi721.txt +++ b/Documentation/rapidio/tsi721.txt @@ -25,6 +25,20 @@ fully compatible with RIONET driver (Ethernet over RapidIO messaging services). This parameter can be changed dynamically. Use CONFIG_RAPIDIO_DEBUG=y to enable debug output at the top level. +- 'dma_desc_per_channel' - This parameter defines number of hardware buffer + descriptors allocated for each registered Tsi721 DMA channel. + Its default value is 128. + +- 'dma_txqueue_sz' - DMA transactions queue size. Defines number of pending + transaction requests that can be accepted by each DMA channel. + Default value is 16. + +- 'dma_sel' - DMA channel selection mask. Bitmask that defines which hardware + DMA channels (0 ... 6) will be registered with DmaEngine core. + If bit is set to 1, the corresponding DMA channel will be registered. + DMA channels not selected by this mask will not be used by this device + driver. Default value is 0x7f (use all channels). + II. Known problems None. -- cgit v1.2.3