From 018768ccc7dc582519b84df593dd8ff1fbd02b55 Mon Sep 17 00:00:00 2001 From: Ian Abbott Date: Tue, 19 Mar 2019 16:54:43 +0000 Subject: [PATCH] staging: comedi: ni_mio_common: use insn->n in ni_eeprom_insn_read() The `insn_read` handler for the EEPROM subdevice on E-series boards (`ni_eeprom_insn_read()`) currently ignores `insn->n` (the number of samples to read) and assumes a single sample is to be read into `data[0]`. Fortunately, the Comedi core ensures that `data[]` has a length of at least 16 so there is no problem with array bounds. The usual Comedi convention for `insn_read` handlers is to read the same channel `insn->n` times into successive elements of `data[]` so let's do that. (Each channel number corresponds to a single EEPROM address.) Since we do not expect the EEPROM data at a particular address to change between readings, let's just read it once and copy the value `insn->n` times. Also, follow the usual Comedi convention and return `insn->n` from the handler to indicate success (although any non-negative value will do). Signed-off-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/ni_mio_common.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/staging/comedi/drivers/ni_mio_common.c b/drivers/staging/comedi/drivers/ni_mio_common.c index e008095..5b397ad 100644 --- a/drivers/staging/comedi/drivers/ni_mio_common.c +++ b/drivers/staging/comedi/drivers/ni_mio_common.c @@ -4507,9 +4507,15 @@ static int ni_eeprom_insn_read(struct comedi_device *dev, struct comedi_insn *insn, unsigned int *data) { - data[0] = ni_read_eeprom(dev, CR_CHAN(insn->chanspec)); + unsigned int val; + unsigned int i; - return 1; + if (insn->n) { + val = ni_read_eeprom(dev, CR_CHAN(insn->chanspec)); + for (i = 0; i < insn->n; i++) + data[i] = val; + } + return insn->n; } static int ni_m_series_eeprom_insn_read(struct comedi_device *dev, -- 2.7.4