From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Chiang Date: Thu, 08 May 2008 20:03:23 +0000 Subject: Re: [PATCH] ia64: allow user to skip_check_sal_cache_flush Message-Id: <20080508200323.GD17222@ldl.fc.hp.com> List-Id: References: <20080507233614.GF5609@ldl.fc.hp.com> In-Reply-To: <20080507233614.GF5609@ldl.fc.hp.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org * Luck, Tony : > > +early_param("skip_check_sal_cache_flush", skip_check_sal_cache_flush); > > Please document this in Documentation/kernel-paramters.txt > > Perhaps this would set the record for the longest kenrel parameter, > but I don't think this is a good thing. Can you abbreviate while > still being descriptive? Sure, how about force_pal_cache_flush? It saves 5 chars and is more explicit about what you're doing. /ac From: Alex Chiang Subject: ia64: allow user to force_pal_cache_flush The sequence executed in check_sal_cache_flush: - pend a timer interrupt - call SAL_CACHE_FLUSH - see if interrupt is still pending can hang HP machines with buggy SAL_CACHE_FLUSH implementations. Provide a kernel command-line argument to allow users skip this check if desired. Using this parameter will force ia64_sal_cache_flush to call ia64_pal_cache_flush() instead of SAL_CACHE_FLUSH. Signed-off-by: Alex Chiang --- diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index cdd5b93..654d630 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -689,6 +689,12 @@ and is between 256 and 4096 characters. It is defined in the file floppy= [HW] See Documentation/floppy.txt. + force_pal_cache_flush + [IA-64] Avoid check_sal_cache_flush which may hang on + buggy SAL_CACHE_FLUSH implementations. Using this + parameter will force ia64_sal_cache_flush to call + ia64_pal_cache_flush instead of SAL_CACHE_FLUSH. + gamecon.map[2|3] [HW,JOY] Multisystem joystick and NES/SNES/PSX pad support via parallel port (up to 5 devices per port) diff --git a/arch/ia64/kernel/sal.c b/arch/ia64/kernel/sal.c index a3022dc..7e02597 100644 --- a/arch/ia64/kernel/sal.c +++ b/arch/ia64/kernel/sal.c @@ -229,6 +229,14 @@ static void __init sal_desc_ap_wakeup(void *p) { } */ static int sal_cache_flush_drops_interrupts; +static int __init +force_pal_cache_flush(char *str) +{ + sal_cache_flush_drops_interrupts = 1; + return 0; +} +early_param("force_pal_cache_flush", force_pal_cache_flush); + void __init check_sal_cache_flush (void) { @@ -237,6 +245,9 @@ check_sal_cache_flush (void) u64 vector, cache_type = 3; struct ia64_sal_retval isrv; + if (sal_cache_flush_drops_interrupts) + return; + cpu = get_cpu(); local_irq_save(flags);