> -----Original Message----- > From: Stephen Warren [mailto:swarren@xxxxxxxxxxxxx] > Sent: Wednesday, March 20, 2013 1:51 AM > To: Venu Byravarasu > Cc: gregkh@xxxxxxxxxxxxxxxxxxx; stern@xxxxxxxxxxxxxxxxxxx; > balbi@xxxxxx; linux-usb@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > linux-tegra@xxxxxxxxxxxxxxx; devicetree-discuss@xxxxxxxxxxxxxxxx > Subject: Re: [PATCH 7/7] usb: phy: registering tegra USB PHY as platform > driver > > On 03/18/2013 06:29 AM, Venu Byravarasu wrote: > > Registered tegra USB PHY as a separate platform driver. > > > > diff --git a/drivers/usb/phy/tegra_usb_phy.c > b/drivers/usb/phy/tegra_usb_phy.c > > > static void tegra_usb_phy_close(struct usb_phy *x) > > { > > if (phy->is_ulpi_phy) > > clk_put(phy->clk); > > phy->clk is obtained using devm_clk_get(). This typically means you > never need to clk_put() it, and if for some reason you really have to, > you should use devm_clk_put() instead of plain clk_put(). Agree, will remove clk_put. > > > @@ -774,23 +667,53 @@ struct tegra_usb_phy > *tegra_usb_phy_open(struct device *dev, int instance, > > > + err = gpio_request(phy->reset_gpio, "ulpi_phy_reset_b"); > > I think you can use devm_gpio_request() here to simplify the error-handling. Sure, will do. > > I wonder why in the ULPI case, all the code is inline here, whereas in > the UTMI case, this simply calls a function. Wouldn't it be more > consistent to have the following code here: > > if (phy->is_ulpi_phy) > err = ulpi_open(); > else > err = utmip_open(); > if (err) > goto fail; Sure, will take care of this in next patch. > > > +static int tegra_usb_phy_probe(struct platform_device *pdev) > > Hmmm. Note that in order to make deferred probe work correctly, all the > gpio_request(), clk_get(), etc. calls that acquire resources from other > drivers must happen here in probe() and not in tegra_usb_phy_open(). In present code tegra_usb_phy_open() is indirectly called via usb_phy_init() from ehci-tegra.c. Between obtaining PHY handle (and hence getting into deferred probe, when it is not available) and calling usb_phy_init, no other USB registers were accessed. Hence I was doing this way. Do you still think it would be better to move gpio and clk APIs to probe? > > > + err = of_property_match_string(np, "dr_mode", "otg"); > > + if (err < 0) { > > + err = of_property_match_string(np, "dr_mode", "gadget"); > > Again, use "peripheral", not "gadget". Will do. > > > +struct usb_phy *tegra_usb_get_phy(struct device_node *dn) > > +{ > > + struct device *dev; > > + struct tegra_usb_phy *tegra_phy; > > + > > + dev = driver_find_device(&tegra_usb_phy_driver.driver, NULL, dn, > > + tegra_usb_phy_match); > > + if (!dev) > > + return ERR_PTR(-EPROBE_DEFER); > > + > > + tegra_phy = dev_get_drvdata(dev); > > + > > + return &tegra_phy->u_phy; > > +} > > I think you need a module_get() somewhere in there, and also need to add > a tegra_usb_put_phy() function too, so you can call module_put() from it. Am not clear on why to add module_get here. Can you plz provide more details? Thanks Stephen, for the review. -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
