From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <3FC55D8C.50200@cs.fujitsu.co.jp> Date: Thu, 27 Nov 2003 11:12:28 +0900 From: Takeharu KATO MIME-Version: 1.0 To: Matt Porter Cc: Felix Domke , linuxppc-embedded@lists.linuxppc.org Subject: Re: 405 Critical Interrupts References: <3FC4D4B5.2030901@elitedvb.net> <20031126134814.A9704@home.com> In-Reply-To: <20031126134814.A9704@home.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: Dear Domke : >>Does CRIT_EXCEPTION work? Is do_IRQ reentrant? Should i use the same >>interrupt processing as a normal hardware interrupt, with the exception >>that only "critical"-flagged interrupts are processed? >> >>Any suggestions? >> >> As far as I know, critical interrupt in ppc4xx archetecture is handled as a kind of unknown Interrupts. So It make system down in 2.6 series (this may also be true in 2.4). In linux kernel , the kernel stack is changed to critical interrupt stack instead of user process's kernel stack when it occuers in super visor mode. So do_IRQ can not be called in crittical interrupt(because it call preempt relevant functions). We have implemeted critical interrupt handling facilites in 2.6 kernel . In this implementation, critical interrupt specific interrupt handling routines. If you need our patch, please contact me(cause we need some periods to prepare the patch). Regards, -- Takeharu KATO Fujitsu Limited Email:tkato@cs.fujitsu.co.jp (ext. 7112-4621) ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/