2014-03-19 16:06 GMT+08:00 Geert Uytterhoeven <[email protected]>: > On Wed, Mar 19, 2014 at 4:53 AM, Axel Lin <[email protected]> wrote: >> Reject transfer if both tx_buf and rx_buf are NULL for non-zero length >> transfer. >> Add the checking in spi core so we can remove the same checking in various >> drivers. > > Just wondering: are there any SPI slave drivers that implement dummy cycles > this way?
I think I found one such case: drivers/net/wireless/libertas/if_spi.c the dummy_trans has non-zero length, and both tx_buf and rx_buf are NULL. But that means it doesn't work with master drivers with this checking, e.g. all drivers using bitbang library has this checking. Regards, Axel -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
