Commit 371a0153 authored by Yadi.hu's avatar Yadi.hu Committed by Wolfram Sang
Browse files

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: default avatarYadi.hu <yadi.hu@windriver.com>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
parent 3be79886
......@@ -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]);
......
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