RE: [ros-cvs] CVS Update: reactos

[Hartmut Birr]

Hi,

this changes prevents from using debug print's in the very early boot phase,
because the processor runs at HIGH_LEVEL and asserts in KfAcquireSpinLock.

- Hartmut

>   -----Original Message-----
>  From: ros-cvs-bounces(a)reactos.com 
>  [mailto:[e-mail]] On Behalf Of 
>  navaraf(a)cvs.reactos.com
>  Sent: Saturday, October 30, 2004 6:30 AM
>  To: ros-cvs(a)reactos.com
>  Subject: [ros-cvs] CVS Update: reactos
>  
>  
>  CVSROOT:	/CVS/ReactOS
>  Module name:	reactos
>  Repository:	reactos/hal/halx86/
>  Changes by:	navaraf(a)mok.osexperts.com	04/10/30 06:30:05
>  
>  Modified files:
>  	reactos/hal/halx86/: display.c 
>  
>  Log message:
>  	- Use KfAcquireSpinLock/KfReleaseSpinLock instead of 
>  KiAcquireSpinLock/KiReleaseSpinLock.
>  
>  _______________________________________________
>  Ros-cvs mailing list
>  Ros-cvs(a)reactos.com
>  http://reactos.com/mailman/listinfo/ros-cvs
>

[Filip Navara]

Hartmut Birr wrote:

>  Hi,
>
> this changes prevents from using debug print's in the very early boot phase,
> because the processor runs at HIGH_LEVEL and asserts in KfAcquireSpinLock.
>
> - Hartmut
>   
>  
The problem is that KiAcquireSpinLock is essentially useless on UP and 
doesn't protect anything. Would you agree with the attached patch?

Regards,
Filip

Index: hal/halx86/display.c
===================================================================
RCS file: /CVS/ReactOS/reactos/hal/halx86/display.c,v
retrieving revision 1.16
diff -u -r1.16 display.c
--- hal/halx86/display.c	30 Oct 2004 13:30:03 -0000	1.16
+++ hal/halx86/display.c	31 Oct 2004 13:33:26 -0000
@@ -682,7 +682,14 @@
 
   pch = String;
 
-  OldIrql = KfAcquireSpinLock(&Lock);
+  if (KeGetCurrentIrql() <= DISPATCH_LEVEL)
+    {
+      OldIrql = KfAcquireSpinLock(&Lock);
+    }
+  else 
+    {
+      OldIrql = HIGH_LEVEL;
+    }
 
   Ki386SaveFlags(Flags);
   Ki386DisableInterrupts();
@@ -749,7 +756,11 @@
   WRITE_PORT_UCHAR((PUCHAR)VGA_CRTC_DATA, (UCHAR)((offset >> 8) & 0xff));
 #endif
   Ki386RestoreFlags(Flags);
-  KfReleaseSpinLock(&Lock, OldIrql);
+
+  if (OldIrql <= DISPATCH_LEVEL)
+    {
+      KfReleaseSpinLock(&Lock, OldIrql);
+    }
 }
 
 VOID STDCALL

[Hartmut Birr]

>   -----Original Message-----
>  From: ros-dev-bounces(a)reactos.com 
>  [mailto:[e-mail]] On Behalf Of Filip Navara
>  Sent: Sunday, October 31, 2004 2:36 PM
>  To: ReactOS Development List
>  Subject: Re: [ros-dev] RE: [ros-cvs] CVS Update: reactos
>  
>  The problem is that KiAcquireSpinLock is essentially useless 
>  on UP and 
>  doesn't protect anything.  
You are right.

>   Would you agree with the attached patch?
>   
I don't agree, because DbgPrint/HalDisplayString can be called on each irql.
We must always raise the irql to HIGH_LEVEL. 

- Hartmut

[Filip Navara]

Hartmut Birr wrote:

> >  Would you agree
> > with the attached patch?
> >  
> I don't agree, because DbgPrint/HalDisplayString can be called on each irql.
> We must always raise the irql to HIGH_LEVEL. 
>   
>  
Oops, sorry. I always forget about MP.

- Filip