From 4022d039a315951e59d95d22e79198d861ce4490 Mon Sep 17 00:00:00 2001 From: Niklas Cassel Date: Wed, 7 Dec 2016 15:20:08 +0100 Subject: net: smmac: allow configuring lower pbl values The driver currently always sets the PBLx8/PBLx4 bit, which means that the pbl values configured via the pbl/txpbl/rxpbl DT properties are always multiplied by 8/4 in the hardware. In order to allow the DT to configure lower pbl values, while at the same time not changing behavior of any existing device trees using the pbl/txpbl/rxpbl settings, add a property to disable the multiplication of the pbl by 8/4 in the hardware. Suggested-by: Rabin Vincent Signed-off-by: Niklas Cassel Acked-by: Alexandre Torgue Signed-off-by: David S. Miller --- Documentation/networking/stmmac.txt | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'Documentation/networking') diff --git a/Documentation/networking/stmmac.txt b/Documentation/networking/stmmac.txt index 6add57374f70..2bb07078f535 100644 --- a/Documentation/networking/stmmac.txt +++ b/Documentation/networking/stmmac.txt @@ -152,8 +152,9 @@ Where: o dma_cfg: internal DMA parameters o pbl: the Programmable Burst Length is maximum number of beats to be transferred in one DMA transaction. - GMAC also enables the 4xPBL by default. + GMAC also enables the 4xPBL by default. (8xPBL for GMAC 3.50 and newer) o txpbl/rxpbl: GMAC and newer supports independent DMA pbl for tx/rx. + o pblx8: Enable 8xPBL (4xPBL for core rev < 3.50). Enabled by default. o fixed_burst/mixed_burst/aal o clk_csr: fixed CSR Clock range selection. o has_gmac: uses the GMAC core. @@ -208,6 +209,7 @@ struct stmmac_dma_cfg { int pbl; int txpbl; int rxpbl; + bool pblx8; int fixed_burst; int mixed_burst; bool aal; @@ -219,6 +221,7 @@ Where: If set, DMA tx will use this value rather than pbl. o rxpbl: Receive Programmable Burst Length. Only for GMAC and newer. If set, DMA rx will use this value rather than pbl. + o pblx8: Enable 8xPBL (4xPBL for core rev < 3.50). Enabled by default. o fixed_burst: program the DMA to use the fixed burst mode o mixed_burst: program the DMA to use the mixed burst mode o aal: Address-Aligned Beats -- cgit v1.2.3