DriverDev-Devel Archive on lore.kernel.org
 help / color / Atom feed
From: Ian Abbott <abbotti@mev.co.uk>
To: devel@driverdev.osuosl.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Ian Abbott <abbotti@mev.co.uk>,
	linux-kernel@vger.kernel.org, stable@vger.kernel.org
Subject: [PATCH 1/4] staging: comedi: ni_6527: fix INSN_CONFIG_DIGITAL_TRIG support
Date: Fri, 17 Jul 2020 15:52:54 +0100
Message-ID: <20200717145257.112660-2-abbotti@mev.co.uk> (raw)
In-Reply-To: <20200717145257.112660-1-abbotti@mev.co.uk>

`ni6527_intr_insn_config()` processes `INSN_CONFIG` comedi instructions
for the "interrupt" subdevice.  When `data[0]` is
`INSN_CONFIG_DIGITAL_TRIG` it is configuring the digital trigger.  When
`data[2]` is `COMEDI_DIGITAL_TRIG_ENABLE_EDGES` it is configuring rising
and falling edge detection for the digital trigger, using a base channel
number (or shift amount) in `data[3]`, a rising edge bitmask in
`data[4]` and falling edge bitmask in `data[5]`.

If the base channel number (shift amount) is greater than or equal to
the number of channels (24) of the digital input subdevice, there are no
changes to the rising and falling edges, so the mask of channels to be
changed can be set to 0, otherwise the mask of channels to be changed,
and the rising and falling edge bitmasks are shifted by the base channel
number before calling `ni6527_set_edge_detection()` to change the
appropriate registers.  Unfortunately, the code is comparing the base
channel (shift amount) to the interrupt subdevice's number of channels
(1) instead of the digital input subdevice's number of channels (24).
Fix it by comparing to 32 because all shift amounts for an `unsigned
int` must be less than that and everything from bit 24 upwards is
ignored by `ni6527_set_edge_detection()` anyway.

Fixes: 110f9e687c1a8 ("staging: comedi: ni_6527: support INSN_CONFIG_DIGITAL_TRIG")
Cc: <stable@vger.kernel.org> # 3.17+
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
---
 drivers/staging/comedi/drivers/ni_6527.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/comedi/drivers/ni_6527.c b/drivers/staging/comedi/drivers/ni_6527.c
index 4d1eccb5041d..4518c2680b7c 100644
--- a/drivers/staging/comedi/drivers/ni_6527.c
+++ b/drivers/staging/comedi/drivers/ni_6527.c
@@ -332,7 +332,7 @@ static int ni6527_intr_insn_config(struct comedi_device *dev,
 		case COMEDI_DIGITAL_TRIG_ENABLE_EDGES:
 			/* check shift amount */
 			shift = data[3];
-			if (shift >= s->n_chan) {
+			if (shift >= 32) {
 				mask = 0;
 				rising = 0;
 				falling = 0;
-- 
2.27.0

_______________________________________________
devel mailing list
devel@linuxdriverproject.org
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel

  reply index

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-17 14:52 [PATCH 0/4] staging: comedi: INSN_CONFIG_DIGITAL_TRIG fixes Ian Abbott
2020-07-17 14:52 ` Ian Abbott [this message]
2020-07-17 14:52 ` [PATCH 2/4] staging: comedi: addi_apci_1032: check INSN_CONFIG_DIGITAL_TRIG shift Ian Abbott
2020-07-17 14:52 ` [PATCH 3/4] staging: comedi: addi_apci_1564: " Ian Abbott
2020-07-17 14:52 ` [PATCH 4/4] staging: comedi: addi_apci_1500: " Ian Abbott
2020-07-20  8:19 ` [PATCH 0/4] staging: comedi: INSN_CONFIG_DIGITAL_TRIG fixes Greg Kroah-Hartman

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200717145257.112660-2-abbotti@mev.co.uk \
    --to=abbotti@mev.co.uk \
    --cc=devel@driverdev.osuosl.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=stable@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

DriverDev-Devel Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/driverdev-devel/0 driverdev-devel/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 driverdev-devel driverdev-devel/ https://lore.kernel.org/driverdev-devel \
		driverdev-devel@linuxdriverproject.org devel@driverdev.osuosl.org
	public-inbox-index driverdev-devel

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.linuxdriverproject.driverdev-devel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git