From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Hutchings Subject: [PATCH 2/5] sfc: Work around unreliable legacy interrupt status Date: Fri, 20 Mar 2009 23:26:41 +0000 Message-ID: <1237591601.3217.8.camel@achroite> References: <1237591540.3217.6.camel@achroite> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, linux-net-drivers@solarflare.com To: David Miller Return-path: Received: from smarthost01.mail.zen.net.uk ([212.23.3.140]:36111 "EHLO smarthost01.mail.zen.net.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1763192AbZCTX0q (ORCPT ); Fri, 20 Mar 2009 19:26:46 -0400 In-Reply-To: <1237591540.3217.6.camel@achroite> Sender: netdev-owner@vger.kernel.org List-ID: In rare cases, reading the legacy interrupt status register can acknowledge an event queue whose attention flag has not yet been set in the register. Until we service this event queue it will not generate any more interrupts. Therefore, as a secondary check, poll the next slot in each active event queue whose flag is not set. Signed-off-by: Ben Hutchings --- drivers/net/sfc/falcon.c | 26 ++++++++++++++------------ 1 files changed, 14 insertions(+), 12 deletions(-) diff --git a/drivers/net/sfc/falcon.c b/drivers/net/sfc/falcon.c index 2ae51fd..92ea614 100644 --- a/drivers/net/sfc/falcon.c +++ b/drivers/net/sfc/falcon.c @@ -1435,6 +1435,7 @@ static irqreturn_t falcon_legacy_interrupt_b0(int irq, void *dev_id) { struct efx_nic *efx = dev_id; efx_oword_t *int_ker = efx->irq_status.addr; + irqreturn_t result = IRQ_NONE; struct efx_channel *channel; efx_dword_t reg; u32 queues; @@ -1449,23 +1450,24 @@ static irqreturn_t falcon_legacy_interrupt_b0(int irq, void *dev_id) if (unlikely(syserr)) return falcon_fatal_interrupt(efx); - if (queues == 0) - return IRQ_NONE; - - efx->last_irq_cpu = raw_smp_processor_id(); - EFX_TRACE(efx, "IRQ %d on CPU %d status " EFX_DWORD_FMT "\n", - irq, raw_smp_processor_id(), EFX_DWORD_VAL(reg)); - /* Schedule processing of any interrupting queues */ - channel = &efx->channel[0]; - while (queues) { - if (queues & 0x01) + efx_for_each_channel(channel, efx) { + if ((queues & 1) || + falcon_event_present( + falcon_event(channel, channel->eventq_read_ptr))) { efx_schedule_channel(channel); - channel++; + result = IRQ_HANDLED; + } queues >>= 1; } - return IRQ_HANDLED; + if (result == IRQ_HANDLED) { + efx->last_irq_cpu = raw_smp_processor_id(); + EFX_TRACE(efx, "IRQ %d on CPU %d status " EFX_DWORD_FMT "\n", + irq, raw_smp_processor_id(), EFX_DWORD_VAL(reg)); + } + + return result; } -- Ben Hutchings, Senior Software Engineer, Solarflare Communications Not speaking for my employer; that's the marketing department's job. They asked us to note that Solarflare product names are trademarked.