| Message ID | 20201214091616.13545-3-Sergey.Semin@baikalelectronics.ru (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | net: stmmac: Fix clocks/reset-related procedures | expand |
On Mon, 14 Dec 2020 12:15:52 +0300, Serge Semin wrote: > In accordance with [1] the permitted PBL values can be set as one of > [1, 2, 4, 8, 16, 32]. The rest of the values results in undefined > behavior. At the same time some of the permitted values can be also > invalid depending on the controller FIFOs size and the data bus width. > Seeing due to having too many variables all the possible PBL property > constraints can't be implemented in the bindings schema, let's extend > the set of permitted PBL values to be as much as the configuration > register supports leaving the undefined behaviour cases for developers > to handle. > > [1] DesignWare Cores Ethernet MAC Universal Databook, Revision 3.73a, > October 2013, p. 380. > > Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> > --- > Documentation/devicetree/bindings/net/snps,dwmac.yaml | 11 +++++++---- > 1 file changed, 7 insertions(+), 4 deletions(-) > Reviewed-by: Rob Herring <robh@kernel.org>
diff --git a/Documentation/devicetree/bindings/net/snps,dwmac.yaml b/Documentation/devicetree/bindings/net/snps,dwmac.yaml index 4b672499f20d..e084fbbf976e 100644 --- a/Documentation/devicetree/bindings/net/snps,dwmac.yaml +++ b/Documentation/devicetree/bindings/net/snps,dwmac.yaml @@ -264,23 +264,26 @@ properties: snps,pbl: description: - Programmable Burst Length (tx and rx) + Programmable Burst Length (tx and rx). Note some of these values + can be still invalid due to HW limitations connected with the data + bus width and the FIFOs depth, so a total length of a single DMA + burst shouldn't exceed half the FIFO depth. $ref: /schemas/types.yaml#definitions/uint32 - enum: [2, 4, 8] + enum: [1, 2, 4, 8, 16, 32] snps,txpbl: description: Tx Programmable Burst Length. If set, DMA tx will use this value rather than snps,pbl. $ref: /schemas/types.yaml#definitions/uint32 - enum: [2, 4, 8] + enum: [1, 2, 4, 8, 16, 32] snps,rxpbl: description: Rx Programmable Burst Length. If set, DMA rx will use this value rather than snps,pbl. $ref: /schemas/types.yaml#definitions/uint32 - enum: [2, 4, 8] + enum: [1, 2, 4, 8, 16, 32] snps,no-pbl-x8: $ref: /schemas/types.yaml#definitions/flag
In accordance with [1] the permitted PBL values can be set as one of [1, 2, 4, 8, 16, 32]. The rest of the values results in undefined behavior. At the same time some of the permitted values can be also invalid depending on the controller FIFOs size and the data bus width. Seeing due to having too many variables all the possible PBL property constraints can't be implemented in the bindings schema, let's extend the set of permitted PBL values to be as much as the configuration register supports leaving the undefined behaviour cases for developers to handle. [1] DesignWare Cores Ethernet MAC Universal Databook, Revision 3.73a, October 2013, p. 380. Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> --- Documentation/devicetree/bindings/net/snps,dwmac.yaml | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)