Re: kern/38758: LOCKDEBUG kernel hangs in esp(4) driver

[Hauke Fath <hf%spg.tu-darmstadt.de@localhost>]

The following reply was made to PR kern/38758; it has been noted by GNATS.

From: Hauke Fath <hf%spg.tu-darmstadt.de@localhost>
To: Izumi Tsutsui <tsutsui%ceres.dti.ne.jp@localhost>
Cc: gnats-bugs%NetBSD.org@localhost, kern-bug-people%NetBSD.org@localhost, 
gnats-admin%NetBSD.org@localhost
Subject: Re: kern/38758: LOCKDEBUG kernel hangs in esp(4) driver
Date: Tue, 27 May 2008 17:26:49 +0200

 At 23:55 Uhr +0900 27.05.2008, Izumi Tsutsui wrote:
 >>   sun3 uses real DMA, doesn't it? Different code paths, probably. The
 >>   mac68k MD code doesn't use simple_lock() anywhere, though.
 >
 >I think the problem is esp interrupts are implicitly enabled
 >by spl2() in esp_quick_dma_go().
 
 Isn't spl2() supposed to block level 2 interrupts (esp here)? With 
 the A/UX interrup mapping of the Quadras, we could in addition to 
 serial interrupts (lvl 4) take interrupts from the onboard SONIC 
 ethernet (lvl 3), the sound chip (lvl 5) and the VIA1 (ADB, clock - 
 lvl 6).
 
 >I have no idea if there is a safe way to enable serial
 >interrupts without enabling esp interrupts.
 
 Commenting out the spl2() .. splhigh() sequence above does not make a 
 difference.
 
        hauke
 
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