From: Éric Piel Date: Wed, 19 Dec 2012 12:03:13 +0000 (+0100) Subject: staging: comedi: fix minimum AO period for NI 625x and NI 628x X-Git-Tag: v3.2.38~105 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=3288bff62342281c6c6cdd2df6e6fc19afe98498;p=karo-tx-linux.git staging: comedi: fix minimum AO period for NI 625x and NI 628x commit 34b55d8c48f4f76044d8f4d6ec3dc786cf210312 upstream. 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 Acked-By: Ian Abbott Signed-off-by: Greg Kroah-Hartman [bwh: Backported to 3.2: drop hunk for a board that's not listed] Signed-off-by: Ben Hutchings --- diff --git a/drivers/staging/comedi/drivers/ni_pcimio.c b/drivers/staging/comedi/drivers/ni_pcimio.c index 9148abdad074..9fee2f2f38b6 100644 --- a/drivers/staging/comedi/drivers/ni_pcimio.c +++ b/drivers/staging/comedi/drivers/ni_pcimio.c @@ -1021,7 +1021,7 @@ 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, @@ -1040,7 +1040,7 @@ 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, @@ -1076,7 +1076,7 @@ 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, @@ -1095,7 +1095,7 @@ 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, @@ -1131,7 +1131,7 @@ 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, @@ -1150,7 +1150,7 @@ 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, @@ -1186,7 +1186,7 @@ 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,