lkml.org 
[lkml]   [2016]   [Sep]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4.4 59/73] i2c-eg20t: fix race between i2c init and interrupt enable
    Date
    4.4-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Yadi.hu <yadi.hu@windriver.com>

    commit 371a015344b6e270e7e3632107d9554ec6d27a6b upstream.

    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 <yadi.hu@windriver.com>
    Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    drivers/i2c/busses/i2c-eg20t.c | 18 +++++++++++-------
    1 file changed, 11 insertions(+), 7 deletions(-)

    --- 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
    /* 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;
    @@ -796,6 +789,17 @@ static int pch_i2c_probe(struct pci_dev
    adap_info->pch_data[i].pch_base_address = base_addr + 0x100 * i;

    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]);


    \
     
     \ /
      Last update: 2016-09-28 11:27    [W:2.164 / U:0.232 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site