>> Since the SPI master might use DMA, tx and rx buffers must live on >> different cache lines. > > Not true. Full duplex tranfsers using a single buffer are > explicitly allowed. Ok, thanks. > If that spi_master driver mis-handles this, it's a bug in that > driver. Well, the driver receives one spi message made of 4 or 6 transfers. It does one at a time, shouldn't it? If the transfer description is intermixed with the data buffer, we fetch a line from ram with not-yet-filled input buffers. So I get invalid data from the analog inputs -- usually zero, as the structure is kzalloced. >> The issue was discussed with Russell King on linux-arm-kernel. > > Gee, but not with the author of that driver or the maintainer of > the SPI framework. Who could have pointed out instantly where > the true bug resides. So, where is it? I don't get it I'm sorry. ps: yes, it's a revB silicon. /alessandro -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
