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From: Bharat Kumar Gogada <bharat.kumar.gogada@xilinx.com>
To: Larry Finger <Larry.Finger@lwfinger.net>,
	"chaoming_li@realsil.com.cn" <chaoming_li@realsil.com.cn>,
	"linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Cc: "kvalo@codeaurora.org" <kvalo@codeaurora.org>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	Ravikiran Gummaluri <rgummal@xilinx.com>
Subject: RE: [PATCH] rtlwifi: rtl8192x: Enabling and disabling hardware interrupts after enabling local irq flags
Date: Fri, 20 Jan 2017 14:14:10 +0000	[thread overview]
Message-ID: <8520D5D51A55D047800579B094147198263CA86D@XAP-PVEXMBX02.xlnx.xilinx.com> (raw)
In-Reply-To: <b2e783f6-fa09-e287-8119-266299cdae22@lwfinger.net>

 > On 01/19/2017 04:14 AM, Bharat Kumar Gogada wrote:
> > -Realtek 8192CE chipset maintains local irq flags after enabling/disabling
> > hardware interrupts.
> > -Hardware interrupts are enabled before enabling the local irq
> > flags(these flags are being checked in interrupt handler),
> > leading to race condition on some RP, where the irq line between
> > bridge and GIC goes high at ASSERT_INTx and goes low only
> > at DEASSERT_INTx. In this kind of RP by the time ASSERT_INTx is seen
> > irq_enable flag is still set to false, resulting in continuous
> > interrupts seen by CPU as DEASSERT_INTx cannot be sent since
> > flag is still false and making CPU stall.
> > -Changing the sequence of setting these irq flags.
> >
> > Signed-off-by: Bharat Kumar Gogada <bharatku@xilinx.com>
> > ---
> 
> This patch should be enhanced with the smb_xx() calls as suggested by by Lino.
> 
> The subject should be changed. I would suggest something like "rtlwifi:
> rtl8192ce: Prevent race condition when enabling interrupts", as it explains the
> condition you are preventing.
> 
> The other PCI drivers also have the same problem. Do you want to prepare the
> patches, or should I do it?
> 
Thanks Larry. Please send out the patches adding the above enhancements suggested by Lino.

Bharat

  parent reply	other threads:[~2017-01-20 14:14 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-01-19 10:14 [PATCH] rtlwifi: rtl8192x: Enabling and disabling hardware interrupts after enabling local irq flags Bharat Kumar Gogada
2017-01-19 14:35 ` Lino Sanfilippo
2017-01-19 18:08   ` Larry Finger
2017-01-19 22:13     ` Lino Sanfilippo
2017-01-20  2:41 ` Larry Finger
2017-01-20 11:14   ` Lino Sanfilippo
2017-01-20 14:14   ` Bharat Kumar Gogada [this message]
2017-01-20 16:30     ` Larry Finger
2017-01-24 10:03       ` Bharat Kumar Gogada

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