Windows System Software -- Consulting, Training, Development -- Unique Expertise, Guaranteed Results
Before Posting...
Please check out the Community Guidelines in the Announcements and Administration Category.More Info on Driver Writing and Debugging
The free OSR Learning Library has more than 50 articles on a wide variety of topics about writing and debugging device drivers and Minifilters. From introductory level to advanced. All the articles have been recently reviewed and updated, and are written using the clear and definitive style you've come to expect from OSR over the years.
Check out The OSR Learning Library at: https://www.osr.com/osr-learning-library/
Keyboard filter driver and caps lock light
OSR_Community_User
Member Posts: 110,217
in NTDEV
Hi,
I have developed a keyboard filter driver for NT that works fine except
that on certain machines
the caps/num/scroll lights do not function once the filter driver is
activated. Hitting the caps lock key,
for instance, will toggle forced capitalization on/off as the caps lock key
is toggled, but the light doesn't
work. I have pruned my filter driver down to pass everything through and
do nothing but attach itself via
IoAttachDeviceToDeviceStack and I get the same results. On most machines
this problem does not
appear.
Any ideas anyone?
thanks,
Greg Dalcher
I have developed a keyboard filter driver for NT that works fine except
that on certain machines
the caps/num/scroll lights do not function once the filter driver is
activated. Hitting the caps lock key,
for instance, will toggle forced capitalization on/off as the caps lock key
is toggled, but the light doesn't
work. I have pruned my filter driver down to pass everything through and
do nothing but attach itself via
IoAttachDeviceToDeviceStack and I get the same results. On most machines
this problem does not
appear.
Any ideas anyone?
thanks,
Greg Dalcher
Howdy, Stranger!
| Upcoming OSR Seminars | ||
|---|---|---|
| OSR has suspended in-person seminars due to the Covid-19 outbreak. But, don't miss your training! Attend via the internet instead! | ||
| Kernel Debugging | 30 January 2023 | Live, Online |
| Developing Minifilters | 20 March 2023 | Live, Online |
| Internals & Software Drivers | 17 April 2023 | Live, Online |
| Writing WDF Drivers | 22 May 2023 | Live, Online |
Comments
I found that the culprit was not double checking that IOCTLs
intercepted were indeed aimed at my
driver. Once I added this double check and made sure I passed along all
IOCTLs not aimed at
my driver, all worked fine. No trouble reported since.
thanks,
Greg
At 02:33 PM 3/1/00 +0200, you wrote:
>Hi,
>I have also developed keyboard filter driver, which does nothing but passes
>all requests through without modifying them. And we also have reports from
>customers that on some NT Workstations caps/num/scroll lock lights are
>always turned on. I haven't investigated the problem yet, but maybe you have
>already found the reasons of this behavior?
>If it is possible, could you please inform me? And if I will find the way to
>fix this problem I will certainly inform you.
>
>Best regards,
>Grigori Shpakov
>
>
>> -----Original Message-----
>> From: Greg Dalcher [SMTP:[email protected]]
>> Sent: Thursday, February 24, 2000 9:24 AM
>> To: NT Developers Interest List
>> Subject: [ntdev] Keyboard filter driver and caps lock light
>>
>> Hi,
>> I have developed a keyboard filter driver for NT that
>> works fine except
>> that on certain machines
>> the caps/num/scroll lights do not function once the filter driver is
>> activated. Hitting the caps lock key,
>> for instance, will toggle forced capitalization on/off as the
>> caps lock key
>> is toggled, but the light doesn't
>> work. I have pruned my filter driver down to pass everything
>> through and
>> do nothing but attach itself via
>> IoAttachDeviceToDeviceStack and I get the same results. On
>> most machines
>> this problem does not
>> appear.
>> Any ideas anyone?
>>
>>
>> thanks,
>> Greg Dalcher
>>
>