Hi,guys
it may more make sense to add a check point on interrupt handler in case
field 'pch_base_address' has been assigned a effective value when an
interrupt arrives.
So something like:
diff --git a/drivers/i2c/busses/i2c-eg20t.c b/drivers/i2c/busses/i2c-eg20t.c
index 137125b..4ac8a49 100644
--- a/drivers/i2c/busses/i2c-eg20t.c
+++ b/drivers/i2c/busses/i2c-eg20t.c
@@ -152,6 +152,7 @@ struct i2c_algo_pch_data {
int pch_buff_mode_en;
u32 pch_event_flag;
bool pch_i2c_xfer_in_progress;
+ bool initflag;
};
/**
@@ -635,6 +636,8 @@ static irqreturn_t pch_i2c_handler(int irq, void *pData)
u32 mode;
for (i = 0, flag = 0; i < adap_info->ch_num; i++) {
+ if (!adap_info->pch_data[i].initflag)
+ continue;
p = adap_info->pch_data[i].pch_base_address;
mode = ioread32(p + PCH_I2CMOD);
mode &= BUFFER_MODE | EEPROM_SR_MODE;
@@ -783,6 +786,7 @@ static int pch_i2c_probe(struct pci_dev *pdev,
for (i = 0; i < adap_info->ch_num; i++) {
pch_adap = &adap_info->pch_data[i].pch_adapter;
adap_info->pch_i2c_suspended = false;
+ adap_info->pch_data[i].initflag = false;
adap_info->pch_data[i].p_adapter_info = adap_info;
@@ -806,6 +810,7 @@ static int pch_i2c_probe(struct pci_dev *pdev,
pch_pci_err(pdev, "i2c_add_adapter[ch:%d]
FAILED\n", i);
goto err_add_adapter;
}
+ adap_info->pch_data[i].initflag = ture;
}
Compared with last one, which one is better?
Yadi
On 2016年08月29日 10:56, Yadi Hu wrote:
From: "Yadi.hu" <yadi.hu@xxxxxxxxxxxxx>
the driver executes request_irq() function before the base address
of i2c registers is remapped in kernel space. If i2c controller
shares an interrupt line with other devices,it is possible that
an interrupt arrives immediately after request_irq() is called.
Since the interrupt handler pch_i2c_handler() is active, it will
read its own register to determine if this interrupt was from
its own device.
At this moment, base address of i2c registers is not remapped
in kernel space yet,so the INT handler access a unknown address
and a error occurs.
Bad IO access at port 0x18 (return inl(port))
Call Trace:
[<c102c733>] warn_slowpath_common+0x73/0xa0
[<c13109f5>] ? bad_io_access+0x45/0x50
[<c13109f5>] ? bad_io_access+0x45/0x50
[<c102c804>] warn_slowpath_fmt+0x34/0x40
[<c13109f5>] bad_io_access+0x45/0x50
[<c1310b62>] ioread32+0x22/0x40
[<c14c60db>] pch_i2c_handler+0x3b/0x120
[<c1092f34>] handle_irq_event_percpu+0x64/0x330
[<c109323b>] handle_irq_event+0x3b/0x60
[<c1095b50>] ? unmask_irq+0x30/0x30
[<c1095ba0>] handle_fasteoi_irq+0x50/0xe0
<IRQ> [<c16e7e78>] ? do_IRQ+0x48/0xc0
[<c16e7f6f>] ? smp_apic_timer_interrupt+0x7f/0x17a
[<c16e7da9>] ? common_interrupt+0x29/0x30
[<c1008ebb>] ? mwait_idle+0x8b/0x2c0
[<c1009e8e>] ? cpu_idle+0x9e/0xc0
[<c16be408>] ? rest_init+0x6c/0x74
[<c19f770a>] ? start_kernel+0x311/0x318
[<c19f7231>] ? repair_env_string+0x51/0x51
[<c19f7078>] ? i386_start_kernel+0x78/0x7d
---[ end trace eb3a1028f468a140 ]---
i2c_eg20t 0000:05:0c.2: pch_i2c_handler :I2C-3 mode(0) is not supported
Signed-off-by: Yadi.hu <yadi.hu@xxxxxxxxxxxxx>
---
drivers/i2c/busses/i2c-eg20t.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)
diff --git a/drivers/i2c/busses/i2c-eg20t.c b/drivers/i2c/busses/i2c-eg20t.c
index 137125b..48483a5 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;
@@ -808,16 +801,23 @@ static int pch_i2c_probe(struct pci_dev *pdev,
}
}
+ 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;
+ }
+
pci_set_drvdata(pdev, adap_info);
pch_pci_dbg(pdev, "returns %d.\n", ret);
return 0;
+err_request_irq:
+ pci_iounmap(pdev, base_addr);
err_add_adapter:
for (j = 0; j < i; j++)
i2c_del_adapter(&adap_info->pch_data[j].pch_adapter);
free_irq(pdev->irq, adap_info);
-err_request_irq:
- pci_iounmap(pdev, base_addr);
err_pci_iomap:
pci_release_regions(pdev);
err_pci_req:
--
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