From patchwork Fri Oct 2 18:14:51 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Hilman X-Patchwork-Id: 51405 X-Patchwork-Delegate: khilman@deeprootsystems.com Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n92IF0ds010864 for ; Fri, 2 Oct 2009 18:15:00 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757990AbZJBSOz (ORCPT ); Fri, 2 Oct 2009 14:14:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757729AbZJBSOz (ORCPT ); Fri, 2 Oct 2009 14:14:55 -0400 Received: from mail-pz0-f177.google.com ([209.85.222.177]:44292 "EHLO mail-pz0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757975AbZJBSOy (ORCPT ); Fri, 2 Oct 2009 14:14:54 -0400 Received: by mail-pz0-f177.google.com with SMTP id 7so1224757pzk.33 for ; Fri, 02 Oct 2009 11:14:58 -0700 (PDT) Received: by 10.114.19.30 with SMTP id 30mr4145437was.134.1254507298462; Fri, 02 Oct 2009 11:14:58 -0700 (PDT) Received: from localhost ([216.254.16.51]) by mx.google.com with ESMTPS id 21sm786643pzk.15.2009.10.02.11.14.57 (version=TLSv1/SSLv3 cipher=RC4-MD5); Fri, 02 Oct 2009 11:14:58 -0700 (PDT) From: Kevin Hilman To: linux-omap@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org, Jon Hunter Subject: [PATCH 1/5] OMAP3: PM: Prevent hang in prcm_interrupt_handler Date: Fri, 2 Oct 2009 11:14:51 -0700 Message-Id: <1254507295-11381-2-git-send-email-khilman@deeprootsystems.com> X-Mailer: git-send-email 1.6.4.3 In-Reply-To: <1254507295-11381-1-git-send-email-khilman@deeprootsystems.com> References: <1254507295-11381-1-git-send-email-khilman@deeprootsystems.com> Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c index 0ff5a6c..1e7aae2 100644 --- a/arch/arm/mach-omap2/pm34xx.c +++ b/arch/arm/mach-omap2/pm34xx.c @@ -51,97 +51,74 @@ static void (*_omap_sram_idle)(u32 *addr, int save_state); static struct powerdomain *mpu_pwrdm; -/* PRCM Interrupt Handler for wakeups */ -static irqreturn_t prcm_interrupt_handler (int irq, void *dev_id) +/* + * PRCM Interrupt Handler Helper Function + * + * The purpose of this function is to clear any wake-up events latched + * in the PRCM PM_WKST_x registers. It is possible that a wake-up event + * may occur whilst attempting to clear a PM_WKST_x register and thus + * set another bit in this register. A while loop is used to ensure + * that any peripheral wake-up events occurring while attempting to + * clear the PM_WKST_x are detected and cleared. + */ +static void prcm_clear_mod_irqs(s16 module, u8 regs) { - u32 wkst, irqstatus_mpu; - u32 fclk, iclk; + u32 wkst, fclk, iclk; + u16 wkst_off = (regs == 3) ? OMAP3430ES2_PM_WKST3 : PM_WKST1; + u16 fclk_off = (regs == 3) ? OMAP3430ES2_CM_FCLKEN3 : CM_FCLKEN1; + u16 iclk_off = (regs == 3) ? CM_ICLKEN3 : CM_ICLKEN1; - /* WKUP */ - wkst = prm_read_mod_reg(WKUP_MOD, PM_WKST); + wkst = prm_read_mod_reg(module, wkst_off); if (wkst) { - iclk = cm_read_mod_reg(WKUP_MOD, CM_ICLKEN); - fclk = cm_read_mod_reg(WKUP_MOD, CM_FCLKEN); - cm_set_mod_reg_bits(wkst, WKUP_MOD, CM_ICLKEN); - cm_set_mod_reg_bits(wkst, WKUP_MOD, CM_FCLKEN); - prm_write_mod_reg(wkst, WKUP_MOD, PM_WKST); - while (prm_read_mod_reg(WKUP_MOD, PM_WKST)) - cpu_relax(); - cm_write_mod_reg(iclk, WKUP_MOD, CM_ICLKEN); - cm_write_mod_reg(fclk, WKUP_MOD, CM_FCLKEN); - } - - /* CORE */ - wkst = prm_read_mod_reg(CORE_MOD, PM_WKST1); - if (wkst) { - iclk = cm_read_mod_reg(CORE_MOD, CM_ICLKEN1); - fclk = cm_read_mod_reg(CORE_MOD, CM_FCLKEN1); - cm_set_mod_reg_bits(wkst, CORE_MOD, CM_ICLKEN1); - cm_set_mod_reg_bits(wkst, CORE_MOD, CM_FCLKEN1); - prm_write_mod_reg(wkst, CORE_MOD, PM_WKST1); - while (prm_read_mod_reg(CORE_MOD, PM_WKST1)) - cpu_relax(); - cm_write_mod_reg(iclk, CORE_MOD, CM_ICLKEN1); - cm_write_mod_reg(fclk, CORE_MOD, CM_FCLKEN1); - } - wkst = prm_read_mod_reg(CORE_MOD, OMAP3430ES2_PM_WKST3); - if (wkst) { - iclk = cm_read_mod_reg(CORE_MOD, CM_ICLKEN3); - fclk = cm_read_mod_reg(CORE_MOD, OMAP3430ES2_CM_FCLKEN3); - cm_set_mod_reg_bits(wkst, CORE_MOD, CM_ICLKEN3); - cm_set_mod_reg_bits(wkst, CORE_MOD, OMAP3430ES2_CM_FCLKEN3); - prm_write_mod_reg(wkst, CORE_MOD, OMAP3430ES2_PM_WKST3); - while (prm_read_mod_reg(CORE_MOD, OMAP3430ES2_PM_WKST3)) - cpu_relax(); - cm_write_mod_reg(iclk, CORE_MOD, CM_ICLKEN3); - cm_write_mod_reg(fclk, CORE_MOD, OMAP3430ES2_CM_FCLKEN3); - } - - /* PER */ - wkst = prm_read_mod_reg(OMAP3430_PER_MOD, PM_WKST); - if (wkst) { - iclk = cm_read_mod_reg(OMAP3430_PER_MOD, CM_ICLKEN); - fclk = cm_read_mod_reg(OMAP3430_PER_MOD, CM_FCLKEN); - cm_set_mod_reg_bits(wkst, OMAP3430_PER_MOD, CM_ICLKEN); - cm_set_mod_reg_bits(wkst, OMAP3430_PER_MOD, CM_FCLKEN); - prm_write_mod_reg(wkst, OMAP3430_PER_MOD, PM_WKST); - while (prm_read_mod_reg(OMAP3430_PER_MOD, PM_WKST)) - cpu_relax(); - cm_write_mod_reg(iclk, OMAP3430_PER_MOD, CM_ICLKEN); - cm_write_mod_reg(fclk, OMAP3430_PER_MOD, CM_FCLKEN); + iclk = cm_read_mod_reg(module, iclk_off); + fclk = cm_read_mod_reg(module, fclk_off); + while (wkst) { + cm_set_mod_reg_bits(wkst, module, iclk_off); + cm_set_mod_reg_bits(wkst, module, fclk_off); + prm_write_mod_reg(wkst, module, wkst_off); + wkst = prm_read_mod_reg(module, wkst_off); + } + cm_write_mod_reg(iclk, module, iclk_off); + cm_write_mod_reg(fclk, module, fclk_off); } +} - if (omap_rev() > OMAP3430_REV_ES1_0) { - /* USBHOST */ - wkst = prm_read_mod_reg(OMAP3430ES2_USBHOST_MOD, PM_WKST); - if (wkst) { - iclk = cm_read_mod_reg(OMAP3430ES2_USBHOST_MOD, - CM_ICLKEN); - fclk = cm_read_mod_reg(OMAP3430ES2_USBHOST_MOD, - CM_FCLKEN); - cm_set_mod_reg_bits(wkst, OMAP3430ES2_USBHOST_MOD, - CM_ICLKEN); - cm_set_mod_reg_bits(wkst, OMAP3430ES2_USBHOST_MOD, - CM_FCLKEN); - prm_write_mod_reg(wkst, OMAP3430ES2_USBHOST_MOD, - PM_WKST); - while (prm_read_mod_reg(OMAP3430ES2_USBHOST_MOD, - PM_WKST)) - cpu_relax(); - cm_write_mod_reg(iclk, OMAP3430ES2_USBHOST_MOD, - CM_ICLKEN); - cm_write_mod_reg(fclk, OMAP3430ES2_USBHOST_MOD, - CM_FCLKEN); +/* + * PRCM Interrupt Handler + * + * The PRM_IRQSTATUS_MPU register indicates if there are any pending + * interrupts from the PRCM for the MPU. These bits must be cleared in + * order to clear the PRCM interrupt. The PRCM interrupt handler is + * implemented to simply clear the PRM_IRQSTATUS_MPU in order to clear + * the PRCM interrupt. Please note that bit 0 of the PRM_IRQSTATUS_MPU + * register indicates that a wake-up event is pending for the MPU and + * this bit can only be cleared if the all the wake-up events latched + * in the various PM_WKST_x registers have been cleared. The interrupt + * handler is implemented using a do-while loop so that if a wake-up + * event occurred during the processing of the prcm interrupt handler + * (setting a bit in the corresponding PM_WKST_x register and thus + * preventing us from clearing bit 0 of the PRM_IRQSTATUS_MPU register) + * this would be handled. + */ +static irqreturn_t prcm_interrupt_handler (int irq, void *dev_id) +{ + u32 irqstatus_mpu; + + do { + prcm_clear_mod_irqs(WKUP_MOD, 1); + prcm_clear_mod_irqs(CORE_MOD, 1); + prcm_clear_mod_irqs(OMAP3430_PER_MOD, 1); + if (omap_rev() > OMAP3430_REV_ES1_0) { + prcm_clear_mod_irqs(CORE_MOD, 3); + prcm_clear_mod_irqs(OMAP3430ES2_USBHOST_MOD, 1); } - } - irqstatus_mpu = prm_read_mod_reg(OCP_MOD, - OMAP3_PRM_IRQSTATUS_MPU_OFFSET); - prm_write_mod_reg(irqstatus_mpu, OCP_MOD, - OMAP3_PRM_IRQSTATUS_MPU_OFFSET); + irqstatus_mpu = prm_read_mod_reg(OCP_MOD, + OMAP3_PRM_IRQSTATUS_MPU_OFFSET); + prm_write_mod_reg(irqstatus_mpu, OCP_MOD, + OMAP3_PRM_IRQSTATUS_MPU_OFFSET); - while (prm_read_mod_reg(OCP_MOD, OMAP3_PRM_IRQSTATUS_MPU_OFFSET)) - cpu_relax(); + } while (prm_read_mod_reg(OCP_MOD, OMAP3_PRM_IRQSTATUS_MPU_OFFSET)); return IRQ_HANDLED; }