From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-wg0-f47.google.com ([74.125.82.47]:40371 "EHLO mail-wg0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759112Ab3GRWmE (ORCPT ); Thu, 18 Jul 2013 18:42:04 -0400 Received: by mail-wg0-f47.google.com with SMTP id l18so3428906wgh.14 for ; Thu, 18 Jul 2013 15:42:03 -0700 (PDT) From: Luis Alves To: linux-media@vger.kernel.org Cc: mchehab@infradead.org, crope@iki.fi, awalls@md.metrocast.net, Luis Alves Subject: [PATCH] cx23885[v2]: Fix IR interrupt storm. Date: Thu, 18 Jul 2013 23:41:57 +0100 Message-Id: <1374187317-4970-1-git-send-email-ljalvs@gmail.com> Sender: linux-media-owner@vger.kernel.org List-ID: Hi all, This path is meant to be up-streamed. Andy has a nice explanation for the interrupt storm when enabling the IR interrupt: The flatiron core (the audio adc) signals the end of its self-test with an interrupt. Since the flatiron irq seems OR-wired with the IR irq the result is this interrupt storm. This i2c tranfers will clear the flatiron interrupts - the left and right channels self-tests. Also as suggested by Andy I moved the i2c transfers to the cx23885 av core interrupt handling worker. If any spurious interrupt happens we silence them. The flatiron has some dedicated register read/write functions but are not exported so Antti just suggested to call the i2c_transfer directly. Tested in the TBS6981 Dual DVB-S2 card. PS: I've found this i2c_transfers in TBS media tree, more precisely in the cx23885-i2c.c file. Regards, Luis Signed-off-by: Luis Alves --- drivers/media/pci/cx23885/cx23885-av.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/drivers/media/pci/cx23885/cx23885-av.c b/drivers/media/pci/cx23885/cx23885-av.c index e958a01..d33570f 100644 --- a/drivers/media/pci/cx23885/cx23885-av.c +++ b/drivers/media/pci/cx23885/cx23885-av.c @@ -29,8 +29,25 @@ void cx23885_av_work_handler(struct work_struct *work) struct cx23885_dev *dev = container_of(work, struct cx23885_dev, cx25840_work); bool handled; + char buffer[2]; + struct i2c_msg msg = { + .addr = 0x98 >> 1, + .flags = 0, + .len = 2, + .buf = buffer, + }; v4l2_subdev_call(dev->sd_cx25840, core, interrupt_service_routine, PCI_MSK_AV_CORE, &handled); + + if (!handled) { + /* clear any pending flatiron interrupts */ + buffer[0] = 0x1f; + buffer[1] = 0x80; + i2c_transfer(&dev->i2c_bus[2].i2c_adap, &msg, 1); + buffer[0] = 0x23; + i2c_transfer(&dev->i2c_bus[2].i2c_adap, &msg, 1); + } + cx23885_irq_enable(dev, PCI_MSK_AV_CORE); } -- 1.7.9.5