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| author | Niklas Cassel <niklas.cassel@axis.com> | 2016-12-07 15:20:08 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-12-08 19:07:10 +0100 |
| commit | 4022d039a315951e59d95d22e79198d861ce4490 (patch) | |
| tree | b6e62d85500ffa47e347dfa4f380f3c69eaabbdf /Documentation/networking | |
| parent | net: stmmac: add support for independent DMA pbl for tx/rx (diff) | |
| download | linux-4022d039a315951e59d95d22e79198d861ce4490.tar.xz linux-4022d039a315951e59d95d22e79198d861ce4490.zip | |
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 <rabinv@axis.com>
Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
Acked-by: Alexandre Torgue <alexandre.torgue@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'Documentation/networking')
| -rw-r--r-- | Documentation/networking/stmmac.txt | 5 |
1 files changed, 4 insertions, 1 deletions
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 |