i2c-eg20t: correct the driver init order of pch_i2c_probe()

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@intel.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

1 files changed, 12 insertions, 10 deletions

diff --git a/drivers/i2c/busses/i2c-eg20t.c b/drivers/i2c/busses/i2c-eg20t.c
index 8cebef49aeac..18936ac9d51c 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);