[PATCH 1/2] i2c-eg20t: correct the driver init order of pch_i2c_probe()

From: Feng Tang
Date: Tue Nov 29 2011 - 02:18:19 EST


Before registering an adapter to i2c subsystem, we need make sure
driver is ready for incoming i2c xfer, becasue the i2c_add_adapter()
may trigger a i2c device driver's proble function which may start
some real i2c xfer. I met this issue when integrating a TSC2007 i2c
touch screen device with the i2c-eg20t driver.

This patch will call request_irq() and hw init before calling
i2c_add_adapter().

Signed-off-by: Feng Tang <feng.tang@xxxxxxxxx>
---
drivers/i2c/busses/i2c-eg20t.c | 22 ++++++++++++----------
1 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/drivers/i2c/busses/i2c-eg20t.c b/drivers/i2c/busses/i2c-eg20t.c
index 8cebef4..18936ac 100644
--- a/drivers/i2c/busses/i2c-eg20t.c
+++ b/drivers/i2c/busses/i2c-eg20t.c
@@ -893,6 +893,13 @@ static int __devinit 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;
@@ -910,28 +917,23 @@ static int __devinit pch_i2c_probe(struct pci_dev *pdev,

pch_adap->dev.parent = &pdev->dev;

+ pch_i2c_init(&adap_info->pch_data[i]);
ret = i2c_add_adapter(pch_adap);
if (ret) {
pch_pci_err(pdev, "i2c_add_adapter[ch:%d] FAILED\n", i);
- goto err_i2c_add_adapter;
+ goto err_add_adapter;
}
-
- pch_i2c_init(&adap_info->pch_data[i]);
- }
- 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_i2c_add_adapter;
}

pci_set_drvdata(pdev, adap_info);
pch_pci_dbg(pdev, "returns %d.\n", ret);
return 0;

-err_i2c_add_adapter:
+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);
--
1.7.1

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