Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754484AbdFNH1f (ORCPT ); Wed, 14 Jun 2017 03:27:35 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:45770 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752602AbdFNH1c (ORCPT ); Wed, 14 Jun 2017 03:27:32 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org A10F9606B7 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=sricharan@codeaurora.org Subject: Re: [PATCH 11/18] spi: qup: properly detect extra interrupts To: Varadarajan Narayanan , broonie@kernel.org, robh+dt@kernel.org, mark.rutland@arm.com, andy.gross@linaro.org, david.brown@linaro.org, linux-spi@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-soc@vger.kernel.org Cc: Matthew McClintock References: <1497419551-21834-1-git-send-email-varada@codeaurora.org> <1497419551-21834-12-git-send-email-varada@codeaurora.org> From: Sricharan R Message-ID: Date: Wed, 14 Jun 2017 12:57:25 +0530 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.1.1 MIME-Version: 1.0 In-Reply-To: <1497419551-21834-12-git-send-email-varada@codeaurora.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2558 Lines: 74 Hi Varada, On 6/14/2017 11:22 AM, Varadarajan Narayanan wrote: > It's possible for a SPI transaction to complete and get another > interrupt and have it processed on the same spi_transfer before the > transfer_one can set it to NULL. > > This masks unexpected interrupts, so let's set the spi_transfer to > NULL in the interrupt once the transaction is done. So we can > properly detect these bad interrupts and print warning messages. > > Signed-off-by: Matthew McClintock > Signed-off-by: Varadarajan Narayanan > --- > drivers/spi/spi-qup.c | 20 +++++++++++--------- > 1 file changed, 11 insertions(+), 9 deletions(-) > > diff --git a/drivers/spi/spi-qup.c b/drivers/spi/spi-qup.c > index bd53e82..1a2a9d9 100644 > --- a/drivers/spi/spi-qup.c > +++ b/drivers/spi/spi-qup.c > @@ -496,13 +496,13 @@ static irqreturn_t spi_qup_qup_irq(int irq, void *dev_id) > struct spi_qup *controller = dev_id; > struct spi_transfer *xfer; > u32 opflags, qup_err, spi_err; > - unsigned long flags; > int error = 0; > + bool done = 0; > > - spin_lock_irqsave(&controller->lock, flags); > + spin_lock(&controller->lock); > xfer = controller->xfer; > controller->xfer = NULL; > - spin_unlock_irqrestore(&controller->lock, flags); > + spin_unlock(&controller->lock); Why change the locking here ? > > qup_err = readl_relaxed(controller->base + QUP_ERROR_FLAGS); > spi_err = readl_relaxed(controller->base + SPI_ERROR_FLAGS); > @@ -556,16 +556,19 @@ static irqreturn_t spi_qup_qup_irq(int irq, void *dev_id) > spi_qup_write(controller, xfer); > } > > - spin_lock_irqsave(&controller->lock, flags); > - controller->error = error; > - controller->xfer = xfer; > - spin_unlock_irqrestore(&controller->lock, flags); > - > /* re-read opflags as flags may have changed due to actions above */ > opflags = readl_relaxed(controller->base + QUP_OPERATIONAL); > > if ((controller->rx_bytes == xfer->len && > (opflags & QUP_OP_MAX_INPUT_DONE_FLAG)) || error) > + done = true; > + > + spin_lock(&controller->lock); > + controller->error = error; > + controller->xfer = done ? NULL : xfer; > + spin_unlock(&controller->lock); > + > + if (done) > complete(&controller->done); > Its not clear, why the driver is setting the controller->xfer = NULL and restoring it inside the irq. This patch seems to fix things on top of that. Regards, Sricharan -- "QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation