Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933445AbaFLNVo (ORCPT ); Thu, 12 Jun 2014 09:21:44 -0400 Received: from comal.ext.ti.com ([198.47.26.152]:42689 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751325AbaFLNVm (ORCPT ); Thu, 12 Jun 2014 09:21:42 -0400 Message-ID: <5399A8D5.6070105@ti.com> Date: Thu, 12 Jun 2014 18:49:17 +0530 From: Sricharan R User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:11.0) Gecko/20120410 Thunderbird/11.0.1 MIME-Version: 1.0 To: Jason Cooper CC: , , , , , , , , , Subject: Re: [PATCH V2 03/19] irqchip: crossbar: Skip some irqs from getting mapped to crossbar References: <1402574007-13987-1-git-send-email-r.sricharan@ti.com> <1402574007-13987-4-git-send-email-r.sricharan@ti.com> <20140612125134.GS8664@titan.lakedaemon.net> In-Reply-To: <20140612125134.GS8664@titan.lakedaemon.net> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jason, On Thursday 12 June 2014 06:21 PM, Jason Cooper wrote: > On Thu, Jun 12, 2014 at 05:23:11PM +0530, Sricharan R wrote: >> From: Nishanth Menon >> >> When, in the system due to varied reasons, interrupts might be unusable >> due to hardware behavior, but register maps do exist, then those interrupts >> should be skipped while mapping irq to crossbars. >> >> Signed-off-by: Nishanth Menon >> Signed-off-by: Sricharan R >> Signed-off-by: Tony Lindgren > > Tony, have you applied these somewhere already? > >> --- >> drivers/irqchip/irq-crossbar.c | 47 ++++++++++++++++++++++++++++++++++++---- >> 1 file changed, 43 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/irqchip/irq-crossbar.c b/drivers/irqchip/irq-crossbar.c >> index 51d4b87..847f6e3 100644 >> --- a/drivers/irqchip/irq-crossbar.c >> +++ b/drivers/irqchip/irq-crossbar.c >> @@ -13,11 +13,13 @@ >> #include >> #include >> #include >> +#include >> #include >> #include >> >> #define IRQ_FREE -1 >> #define IRQ_RESERVED -2 >> +#define IRQ_SKIP -3 >> #define GIC_IRQ_START 32 >> >> /* >> @@ -34,6 +36,16 @@ struct crossbar_device { >> void (*write) (int, int); >> }; >> >> +/** >> + * struct crossbar_data: Platform specific data >> + * @irqs_unused: array of irqs that cannot be used because of hw erratas >> + * @size: size of the irqs_unused array >> + */ >> +struct crossbar_data { >> + const uint *irqs_unused; >> + const uint size; >> +}; >> + >> static struct crossbar_device *cb; >> >> static inline void crossbar_writel(int irq_no, int cb_no) >> @@ -119,10 +131,12 @@ const struct irq_domain_ops routable_irq_domain_ops = { >> .xlate = crossbar_domain_xlate >> }; >> >> -static int __init crossbar_of_init(struct device_node *node) >> +static int __init crossbar_of_init(struct device_node *node, >> + const struct crossbar_data *data) >> { >> int i, size, max, reserved = 0, entry; >> const __be32 *irqsr; >> + const int *irqsk = NULL; >> >> cb = kzalloc(sizeof(*cb), GFP_KERNEL); >> >> @@ -194,6 +208,22 @@ static int __init crossbar_of_init(struct device_node *node) >> reserved += size; >> } >> >> + /* Skip the ones marked as unused */ >> + if (data) { >> + irqsk = data->irqs_unused; >> + size = data->size; >> + >> + for (i = 0; i < size; i++) { >> + entry = irqsk[i]; >> + >> + if (entry > max) { >> + pr_err("Invalid skip entry\n"); >> + goto err3; >> + } >> + cb->irq_map[entry] = IRQ_SKIP; >> + } >> + } >> + >> register_routable_domain_ops(&routable_irq_domain_ops); >> return 0; >> >> @@ -208,18 +238,27 @@ err1: >> return -ENOMEM; >> } >> >> +/* irq number 10 cannot be used because of hw bug */ >> +int dra_irqs_unused[] = { 10 }; >> +struct crossbar_data cb_dra_data = { dra_irqs_unused, >> + ARRAY_SIZE(dra_irqs_unused) }; >> + >> static const struct of_device_id crossbar_match[] __initconst = { >> - { .compatible = "ti,irq-crossbar" }, >> + { .compatible = "ti,irq-crossbar", .data = &cb_dra_data }, >> {} >> }; > > This is a bug in all implementations of this IP? Or, a specific > SoC's implementation? Would this be better expressed in the dts via a > property? Can we expect future implementations to be fixed? > > thx, > > Jason. Infact this and PATCH#10 should be merged. I will change that. So in Socs's (2 so far) that do have a crossbar, some irqs are mapped through a crossbar and some are directly wired to the irqchip. These 'unused irqs' are those which are directly wired but they still have a crossbar register. Their routing cannot be changed. So this is not really expected usage of the crossbar hw ip. We initially thought having a dts property separately for this, but took this path to avoid loading the dts with additional bindings which may not be generic. Regards, Sricharan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/