The minimum period was set to 357 ns, while the divider for these boards is 50 ns. This prevented to output at maximum speed as ni_ao_cmdtest() would return 357 but would not accept it. Not sure why it was set to 357 ns (this was done before the git history, which starts 5 years ago). My guess is that it comes from reading the specification stating a 2.8 MHz rate (~ 357 ns). The latest specification states a 2.86 MHz rate (~ 350 ns), which makes a lot more sense. Tested on a pci-6251. Signed-off-by: Éric Piel <piel@xxxxxxxxxx> Cc: Ian Abbott <abbotti@xxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: <devel@xxxxxxxxxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> --- drivers/staging/comedi/drivers/ni_pcimio.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/drivers/staging/comedi/drivers/ni_pcimio.c b/drivers/staging/comedi/drivers/ni_pcimio.c index aaac0b2..fd1662b 100644 --- a/drivers/staging/comedi/drivers/ni_pcimio.c +++ b/drivers/staging/comedi/drivers/ni_pcimio.c @@ -963,7 +963,7 @@ static const struct ni_board_struct ni_boards[] = { .ao_range_table = &range_ni_M_625x_ao, .reg_type = ni_reg_625x, .ao_unipolar = 0, - .ao_speed = 357, + .ao_speed = 350, .num_p0_dio_channels = 8, .caldac = {caldac_none}, .has_8255 = 0, @@ -982,7 +982,7 @@ static const struct ni_board_struct ni_boards[] = { .ao_range_table = &range_ni_M_625x_ao, .reg_type = ni_reg_625x, .ao_unipolar = 0, - .ao_speed = 357, + .ao_speed = 350, .num_p0_dio_channels = 8, .caldac = {caldac_none}, .has_8255 = 0, @@ -1001,7 +1001,7 @@ static const struct ni_board_struct ni_boards[] = { .ao_range_table = &range_ni_M_625x_ao, .reg_type = ni_reg_625x, .ao_unipolar = 0, - .ao_speed = 357, + .ao_speed = 350, .num_p0_dio_channels = 8, .caldac = {caldac_none}, .has_8255 = 0, @@ -1037,7 +1037,7 @@ static const struct ni_board_struct ni_boards[] = { .ao_range_table = &range_ni_M_625x_ao, .reg_type = ni_reg_625x, .ao_unipolar = 0, - .ao_speed = 357, + .ao_speed = 350, .num_p0_dio_channels = 32, .caldac = {caldac_none}, .has_8255 = 0, @@ -1056,7 +1056,7 @@ static const struct ni_board_struct ni_boards[] = { .ao_range_table = &range_ni_M_625x_ao, .reg_type = ni_reg_625x, .ao_unipolar = 0, - .ao_speed = 357, + .ao_speed = 350, .num_p0_dio_channels = 32, .caldac = {caldac_none}, .has_8255 = 0, @@ -1092,7 +1092,7 @@ static const struct ni_board_struct ni_boards[] = { .ao_range_table = &range_ni_M_628x_ao, .reg_type = ni_reg_628x, .ao_unipolar = 1, - .ao_speed = 357, + .ao_speed = 350, .num_p0_dio_channels = 8, .caldac = {caldac_none}, .has_8255 = 0, @@ -1111,7 +1111,7 @@ static const struct ni_board_struct ni_boards[] = { .ao_range_table = &range_ni_M_628x_ao, .reg_type = ni_reg_628x, .ao_unipolar = 1, - .ao_speed = 357, + .ao_speed = 350, .num_p0_dio_channels = 8, .caldac = {caldac_none}, .has_8255 = 0, @@ -1147,7 +1147,7 @@ static const struct ni_board_struct ni_boards[] = { .ao_range_table = &range_ni_M_628x_ao, .reg_type = ni_reg_628x, .ao_unipolar = 1, - .ao_speed = 357, + .ao_speed = 350, .num_p0_dio_channels = 32, .caldac = {caldac_none}, .has_8255 = 0, -- 1.7.9.5 _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/devel