For aesthetics, init the dmalen[01] local variables when they are declared.
Use a local variable, 'scan_bytes', for the (devpriv->ai_n_realscanlen << 1)
calculation. For aesthetics and clarification, use comedi_bytes_per_sample()
instead of the '<< 1' shift to calculate the value.
The local variable 'i' is badly named. Remove it and use a local variable
'tmp' where it is used.
When checking the DMA buffer lengths for non-neverending commands the
scan length calculation, (devpriv->ai_n_realscanlen << 1) * cmd->stop_arg,
could overflow. Use and unsigned long long local variable to hold the
calculation and avoid the overflow.
Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: Ian Abbott <abbotti@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/comedi/drivers/adl_pci9118.c | 67 +++++++++++++---------------
1 file changed, 31 insertions(+), 36 deletions(-)
diff --git a/drivers/staging/comedi/drivers/adl_pci9118.c b/drivers/staging/comedi/drivers/adl_pci9118.c
index e2302cb..0dff1db 100644
--- a/drivers/staging/comedi/drivers/adl_pci9118.c
+++ b/drivers/staging/comedi/drivers/adl_pci9118.c
@@ -801,10 +801,11 @@ static int pci9118_ai_setup_dma(struct comedi_device *dev,
struct comedi_cmd *cmd = &s->async->cmd;
struct pci9118_dmabuf *dmabuf0 = &devpriv->dmabuf[0];
struct pci9118_dmabuf *dmabuf1 = &devpriv->dmabuf[1];
- unsigned int dmalen0, dmalen1, i;
+ unsigned int dmalen0 = dmabuf0->size;
+ unsigned int dmalen1 = dmabuf1->size;
+ unsigned int scan_bytes = devpriv->ai_n_realscanlen *
+ comedi_bytes_per_sample(s);
- dmalen0 = dmabuf0->size;
- dmalen1 = dmabuf1->size;
/* isn't output buff smaller that our DMA buff? */
if (dmalen0 > s->async->prealloc_bufsz) {
/* align to 32bit down */
@@ -817,15 +818,15 @@ static int pci9118_ai_setup_dma(struct comedi_device *dev,
/* we want wake up every scan? */
if (devpriv->ai_flags & CMDF_WAKE_EOS) {
- if (dmalen0 < (devpriv->ai_n_realscanlen << 1)) {
+ if (dmalen0 < scan_bytes) {
/* uff, too short DMA buffer, disable EOS support! */
devpriv->ai_flags &= (~CMDF_WAKE_EOS);
dev_info(dev->class_dev,
"WAR: DMA0 buf too short, can't support CMDF_WAKE_EOS (%d<%d)\n",
- dmalen0, devpriv->ai_n_realscanlen << 1);
+ dmalen0, scan_bytes);
} else {
/* short first DMA buffer to one scan */
- dmalen0 = devpriv->ai_n_realscanlen << 1;
+ dmalen0 = scan_bytes;
if (dmalen0 < 4) {
dev_info(dev->class_dev,
"ERR: DMA0 buf len bug? (%d<4)\n",
@@ -835,15 +836,15 @@ static int pci9118_ai_setup_dma(struct comedi_device *dev,
}
}
if (devpriv->ai_flags & CMDF_WAKE_EOS) {
- if (dmalen1 < (devpriv->ai_n_realscanlen << 1)) {
+ if (dmalen1 < scan_bytes) {
/* uff, too short DMA buffer, disable EOS support! */
devpriv->ai_flags &= (~CMDF_WAKE_EOS);
dev_info(dev->class_dev,
"WAR: DMA1 buf too short, can't support CMDF_WAKE_EOS (%d<%d)\n",
- dmalen1, devpriv->ai_n_realscanlen << 1);
+ dmalen1, scan_bytes);
} else {
/* short second DMA buffer to one scan */
- dmalen1 = devpriv->ai_n_realscanlen << 1;
+ dmalen1 = scan_bytes;
if (dmalen1 < 4) {
dev_info(dev->class_dev,
"ERR: DMA1 buf len bug? (%d<4)\n",
@@ -855,45 +856,39 @@ static int pci9118_ai_setup_dma(struct comedi_device *dev,
/* transfer without CMDF_WAKE_EOS */
if (!(devpriv->ai_flags & CMDF_WAKE_EOS)) {
+ unsigned int tmp;
+
/* if it's possible then align DMA buffers to length of scan */
- i = dmalen0;
- dmalen0 =
- (dmalen0 / (devpriv->ai_n_realscanlen << 1)) *
- (devpriv->ai_n_realscanlen << 1);
+ tmp = dmalen0;
+ dmalen0 = (dmalen0 / scan_bytes) * scan_bytes;
dmalen0 &= ~3L;
if (!dmalen0)
- dmalen0 = i; /* uff. very long scan? */
- i = dmalen1;
- dmalen1 =
- (dmalen1 / (devpriv->ai_n_realscanlen << 1)) *
- (devpriv->ai_n_realscanlen << 1);
+ dmalen0 = tmp; /* uff. very long scan? */
+ tmp = dmalen1;
+ dmalen1 = (dmalen1 / scan_bytes) * scan_bytes;
dmalen1 &= ~3L;
if (!dmalen1)
- dmalen1 = i; /* uff. very long scan? */
+ dmalen1 = tmp; /* uff. very long scan? */
/*
* if measure isn't neverending then test, if it fits whole
* into one or two DMA buffers
*/
if (!devpriv->ai_neverending) {
+ unsigned long long scanlen;
+
+ scanlen = (unsigned long long)scan_bytes *
+ cmd->stop_arg;
+
/* fits whole measure into one DMA buffer? */
- if (dmalen0 >
- ((devpriv->ai_n_realscanlen << 1) *
- cmd->stop_arg)) {
- dmalen0 =
- (devpriv->ai_n_realscanlen << 1) *
- cmd->stop_arg;
+ if (dmalen0 > scanlen) {
+ dmalen0 = scanlen;
dmalen0 &= ~3L;
- } else { /*
- * fits whole measure into
- * two DMA buffer?
- */
- if (dmalen1 >
- ((devpriv->ai_n_realscanlen << 1) *
- cmd->stop_arg - dmalen0))
- dmalen1 =
- (devpriv->ai_n_realscanlen << 1) *
- cmd->stop_arg - dmalen0;
- dmalen1 &= ~3L;
+ } else {
+ /* fits whole measure into two DMA buffer? */
+ if (dmalen1 > (scanlen - dmalen0)) {
+ dmalen1 = scanlen - dmalen0;
+ dmalen1 &= ~3L;
+ }
}
}
}
--
2.5.1
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