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SubjectRe: reserve= not working, drivers fail to do check_region
   Date: 	Fri, 10 Jan 1997 10:32:34 +0100
From: Thomas Sailer <>

This as a very dangerous idea. There are currently drivers competing
for the same hardware resource. For example the serial and the baycom
drivers. When the serial driver gets loaded, it grabs all serial
ports it finds. Now when someone afterwards loads the baycom driver
and tells it to use a specific COM port, it would, using your idea,
use this specific port and the serial driver would not know anything
about that. This would result in two drivers trying to drive
the same hardware with different ideas :-)
There is now way the baycom driver can reliably detect if a baycom
modem really sits at any specific COM port.

The serial driver only grabs reserves io regions and irq's for serial
ports when the serial ports are actually open, and it checks to see if
the ioports and irq's are available when the serial port is actually

Thus, if a baycom driver is loaded, and grabs a COM port, the serial
driver will return EBUSY when a attempt is made to open the COM port via
the serial driver.

- Ted

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