From 371a015344b6e270e7e3632107d9554ec6d27a6b Mon Sep 17 00:00:00 2001 From: "Yadi.hu" Date: Sun, 18 Sep 2016 18:52:31 +0800 Subject: [PATCH] i2c-eg20t: fix race between i2c init and interrupt enable the eg20t driver call request_irq() function before the pch_base_address, base address of i2c controller's register, is assigned an effective value. there is one possible scenario that an interrupt which isn't inside eg20t arrives immediately after request_irq() is executed when i2c controller shares an interrupt number with others. since the interrupt handler pch_i2c_handler() has already active as shared action, it will be called and read its own register to determine if this interrupt is from itself. At that moment, since base address of i2c registers is not remapped in kernel space yet,so the INT handler will access an illegal address and then a error occurs. Signed-off-by: Yadi.hu Signed-off-by: Wolfram Sang Cc: stable@kernel.org --- drivers/i2c/busses/i2c-eg20t.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/drivers/i2c/busses/i2c-eg20t.c b/drivers/i2c/busses/i2c-eg20t.c index 137125b5eae7..5ce71ce7b6c4 100644 --- a/drivers/i2c/busses/i2c-eg20t.c +++ b/drivers/i2c/busses/i2c-eg20t.c @@ -773,13 +773,6 @@ static int pch_i2c_probe(struct pci_dev *pdev, /* Set the number of I2C channel instance */ adap_info->ch_num = id->driver_data; - ret = request_irq(pdev->irq, pch_i2c_handler, IRQF_SHARED, - KBUILD_MODNAME, adap_info); - if (ret) { - pch_pci_err(pdev, "request_irq FAILED\n"); - goto err_request_irq; - } - for (i = 0; i < adap_info->ch_num; i++) { pch_adap = &adap_info->pch_data[i].pch_adapter; adap_info->pch_i2c_suspended = false; @@ -797,6 +790,17 @@ static int pch_i2c_probe(struct pci_dev *pdev, pch_adap->dev.of_node = pdev->dev.of_node; pch_adap->dev.parent = &pdev->dev; + } + + ret = request_irq(pdev->irq, pch_i2c_handler, IRQF_SHARED, + KBUILD_MODNAME, adap_info); + if (ret) { + pch_pci_err(pdev, "request_irq FAILED\n"); + goto err_request_irq; + } + + for (i = 0; i < adap_info->ch_num; i++) { + pch_adap = &adap_info->pch_data[i].pch_adapter; pch_i2c_init(&adap_info->pch_data[i]); -- 2.20.1