From 56556577d9c4b4528935ddfc5635953c956d7fc9 Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Tue, 29 Apr 2014 11:08:33 -0700 Subject: [PATCH] staging: comedi: adv_pci1710: don't check the chanlist twice The chanlist is checked in Step 5 of the (*do_cmdtest) there is no reason to check it again in the (*do_cmd). The only reason its done again is to get the actual 'seglen', the non-repeating length of the chanlist. Save the 'seglen' found by pci171x_ai_check_chanlist() in the private data and use that in the (*do_cmd). Rename the private data member to clarify it. Also, remove the unused 'act_chanlist_pos' member from the private data. Refactor the error handling in pci171x_ai_check_chanlist() so it returns and errno for failure and 0 for success. Signed-off-by: H Hartley Sweeten Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/adv_pci1710.c | 34 ++++++++++---------- 1 file changed, 17 insertions(+), 17 deletions(-) diff --git a/drivers/staging/comedi/drivers/adv_pci1710.c b/drivers/staging/comedi/drivers/adv_pci1710.c index da1309b80691..f83c382c1eaa 100644 --- a/drivers/staging/comedi/drivers/adv_pci1710.c +++ b/drivers/staging/comedi/drivers/adv_pci1710.c @@ -310,8 +310,7 @@ struct pci1710_private { unsigned int ai_et_MuxVal; unsigned int ai_et_div1, ai_et_div2; unsigned int act_chanlist[32]; /* list of scanned channel */ - unsigned char act_chanlist_len; /* len of scanlist */ - unsigned char act_chanlist_pos; /* actual position in MUX list */ + unsigned char saved_seglen; /* len of the non-repeating chanlist */ unsigned char da_ranges; /* copy of D/A outpit range register */ unsigned short ao_data[4]; /* data output buffer */ unsigned int cnt0_write_wait; /* after a write, wait for update of the @@ -330,6 +329,7 @@ static int pci171x_ai_check_chanlist(struct comedi_device *dev, struct comedi_subdevice *s, struct comedi_cmd *cmd) { + struct pci1710_private *devpriv = dev->private; unsigned int chan0 = CR_CHAN(cmd->chanlist[0]); unsigned int last_aref = CR_AREF(cmd->chanlist[0]); unsigned int next_chan = (chan0 + 1) % s->n_chan; @@ -337,8 +337,10 @@ static int pci171x_ai_check_chanlist(struct comedi_device *dev, unsigned int seglen; int i; - if (cmd->chanlist_len == 1) - return 1; /* seglen=1 */ + if (cmd->chanlist_len == 1) { + devpriv->saved_seglen = cmd->chanlist_len; + return 0; + } /* first channel is always ok */ chansegment[0] = cmd->chanlist[0]; @@ -353,7 +355,7 @@ static int pci171x_ai_check_chanlist(struct comedi_device *dev, if (aref == AREF_DIFF && (chan & 1)) { dev_err(dev->class_dev, "Odd channel cannot be differential input!\n"); - return 0; + return -EINVAL; } if (last_aref == AREF_DIFF) @@ -362,7 +364,7 @@ static int pci171x_ai_check_chanlist(struct comedi_device *dev, dev_err(dev->class_dev, "channel list must be continuous! chanlist[%i]=%d but must be %d or %d!\n", i, chan, next_chan, chan0); - return 0; + return -EINVAL; } /* next correct channel in list */ @@ -381,10 +383,12 @@ static int pci171x_ai_check_chanlist(struct comedi_device *dev, CR_CHAN(cmd->chanlist[i % seglen]), CR_RANGE(cmd->chanlist[i % seglen]), CR_AREF(chansegment[i % seglen])); - return 0; + return -EINVAL; } } - return seglen; + devpriv->saved_seglen = seglen; + + return 0; } static void setup_channel_list(struct comedi_device *dev, @@ -396,9 +400,6 @@ static void setup_channel_list(struct comedi_device *dev, struct pci1710_private *devpriv = dev->private; unsigned int i, range, chanprog; - devpriv->act_chanlist_len = seglen; - devpriv->act_chanlist_pos = 0; - for (i = 0; i < seglen; i++) { /* store range list to card */ chanprog = muxonechan[CR_CHAN(chanlist[i])]; outw(chanprog, dev->iobase + PCI171x_MUX); /* select channel */ @@ -953,7 +954,6 @@ static int pci171x_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s) struct pci1710_private *devpriv = dev->private; struct comedi_cmd *cmd = &s->async->cmd; unsigned int divisor1 = 0, divisor2 = 0; - unsigned int seglen; int mode; if (cmd->convert_src == TRIG_TIMER) { @@ -967,10 +967,8 @@ static int pci171x_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s) start_pacer(dev, -1, 0, 0); /* stop pacer */ - seglen = pci171x_ai_check_chanlist(dev, s, cmd); - if (seglen < 1) - return -EINVAL; - setup_channel_list(dev, s, cmd->chanlist, cmd->chanlist_len, seglen); + setup_channel_list(dev, s, cmd->chanlist, cmd->chanlist_len, + devpriv->saved_seglen); outb(0, dev->iobase + PCI171x_CLRFIFO); outb(0, dev->iobase + PCI171x_CLRINT); @@ -1104,7 +1102,9 @@ static int pci171x_ai_cmdtest(struct comedi_device *dev, /* Step 5: check channel list */ - if (!pci171x_ai_check_chanlist(dev, s, cmd)) + err |= pci171x_ai_check_chanlist(dev, s, cmd); + + if (err) return 5; return 0; -- 2.20.1