(Resending this bug report to linux-spi as requested, first reported to nios2-...@lists.rocketboards.org.)
Hello Using spi-altera from (and with) mainline kernel 4.0rc3 gives a kernel panic on first attempted SPI transfer. After debugging, it seems to be caused by commit 24778be2 which removed the empty implementation of altera_spi_setupxfer() (the function was temporarily added back in commit 103ccee4 because of a perceived problem, and then removed again in commit 30af9b55). This causes two problems: 1) Since spi-altera doesn't zero-initialize the spi_bitbang struct, bitbang->setup_transfer points to a random memory location, obviously giving a kernel panic when it's called. 2) Even if I zero-initialize it, spi-bitbang reacts to this by calling its built-in setup function spi_bitbang_setup_transfer(), and this function tries to write to fields in the struct pointed out by spi->controller_state. However, spi->controller_state is NULL (at least for me), so this again gives a kernel panic due to NULL pointer dereference. So the easiest way I could find to get the driver working is by reverting the change mentioned above, adding back an empty implementation of altera_spi_setupxfer(). Best regards, Pelle -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
