Hans-Christian Noren Egtvedt <egtvedt@xxxxxxxxxxxx> writes: > Around Sun 24 Jan 2016 20:19:46 +0000 or thereabout, Måns Rullgård wrote: >> Hans-Christian Noren Egtvedt <egtvedt@xxxxxxxxxxxx> writes: >>> Around Sun 24 Jan 2016 19:21:50 +0000 or thereabout, Mans Rullgard wrote: >>>> From: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> >>>> >>>> The source and destination masters are reflecting buses or their layers to >>>> where the different devices can be connected. The patch changes the master >>>> names to reflect which one is related to which independently on the transfer >>>> direction. >>>> >>>> The outcome of the change is that the memory data width is now always limited >>>> by a data width of the master which is dedicated to communicate to memory. >>>> >>>> The patch will not break anything since all current users have the same data >>>> width for all masters. Though it would be nice to revisit avr32 plaforms to >>>> check what is the actual hardware topology is used there. It seems that it has >>>> one bus and two masters on it as stated by Table 8-2, that's why everything >>>> works independently on the master in use. The purpose of the sequential patch >>>> is to fix the driver for configuration of more that one bus. >>> >>> Not entirely sure what you want to have confirmed here. There are multiple >>> masters and slaves on the HMATRIX internal bus on AVR32, and the DMA >>> controller supports up to three simultaneous configurations. >>> >>> Sounds good to support configuration of more than one bus. I thought we >>> always did support that? Perhaps it was a non-standard avr32 implementation. >> >> The DW DMA controller on the AT32AP7000 serves the MCI, AC97, and ABDAC >> peripherals. It appears to work regardless of the values put in the >> various master select fields. Perhaps the topology is hardwired in the >> DMA controller and those fields are ignored. The AVR32 works both >> before and after this patch series, the main purpose of which (at least >> my patches) is to fix the SATA driver on 460EX. > > DEST_PER and SRC_PER in the DMA controller selects this, numbers placed here > should match the table you most likely found, 9-3. > > Wiring the handshake connections is done with the struct dw_dma_slave src_id > or dst_id member, depending on data direction. Configured in the at32ap700x.c > machine code. > > It is not hard wired on avr32, as there are not one-to-one configurations and > masters. This is about the SMS (Source Master Select) and DMS (Destination Master Select) fields in the CTLxL register and the LMS (List Master Select) field in the LLPx register. >>>> The change is done in the assumption that src_master and dst_master are >>>> reflecting a connection to the memory and peripheral correspondently on all >>>> platforms except 460ex. > > OK, I have no knowledge about the 460ex. > >>>> Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> >>>> Signed-off-by: Mans Rullgard <mans@xxxxxxxxx> >>> >>> For the avr32 related stuff: >>> >>> Acked-by: Hans-Christian Egtvedt <egtvedt@xxxxxxxxxxxx> >>> >>>> --- >>>> Documentation/devicetree/bindings/dma/snps-dma.txt | 4 ++-- >>>> arch/avr32/mach-at32ap/at32ap700x.c | 16 ++++++++-------- >>>> drivers/ata/sata_dwc_460ex.c | 4 ++-- >>>> drivers/dma/dw/core.c | 15 +++++++-------- >>>> drivers/dma/dw/platform.c | 12 ++++++------ >>>> drivers/dma/dw/regs.h | 4 ++-- >>>> drivers/spi/spi-pxa2xx-pci.c | 8 ++++---- >>>> drivers/tty/serial/8250/8250_pci.c | 8 ++++---- >>>> include/linux/platform_data/dma-dw.h | 8 ++++---- >>>> 9 files changed, 39 insertions(+), 40 deletions(-) >>> >>> <snipp diff> > -- > Best regards, Hans-Christian Egtvedt -- Måns Rullgård -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
