| Message ID | 1432727283-20303-4-git-send-email-chunfeng.yun@mediatek.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, May 27, 2015 at 07:48:00PM +0800, chunfeng.yun@mediatek.com wrote: > From: Chunfeng Yun <chunfeng.yun@mediatek.com> > > find the phy driver before add primary usb_hcd to avoid acessing > xHCI register which may hangup the system when the phy is not loaded > yet and the related powers or clocks put in phy driver are not > enabled. it seems like the same clock is needed by PHY and XHCI. This patch looks incorrect.
On Wed, 2015-05-27 at 07:18 -0500, Felipe Balbi wrote: > On Wed, May 27, 2015 at 07:48:00PM +0800, chunfeng.yun@mediatek.com wrote: > > From: Chunfeng Yun <chunfeng.yun@mediatek.com> > > > > find the phy driver before add primary usb_hcd to avoid acessing > > xHCI register which may hangup the system when the phy is not loaded > > yet and the related powers or clocks put in phy driver are not > > enabled. > > it seems like the same clock is needed by PHY and XHCI. This patch looks > incorrect. Hi, I agree that the driver should enable clock it used by itself and not depends on init order. This should be fixed. But in general, I think it make sense to only add hcd after all required resource are ready. At least it remove unnecessary calls to usb_add_hcd/usb_remove_hcd. Is it better if the commit message is changed to something like the below? Currently xhci_plat_probe() call usb_add_hcd before trying to init the phy. However if the phy is not ready at the moment, it have to remove the hcd and probe again later Change the init order so we only add hcd when all required resource are ready. Joe.C
On 01.06.2015 17:52, Yingjoe Chen wrote: > On Wed, 2015-05-27 at 07:18 -0500, Felipe Balbi wrote: >> On Wed, May 27, 2015 at 07:48:00PM +0800, chunfeng.yun@mediatek.com wrote: >>> From: Chunfeng Yun <chunfeng.yun@mediatek.com> >>> >>> find the phy driver before add primary usb_hcd to avoid acessing >>> xHCI register which may hangup the system when the phy is not loaded >>> yet and the related powers or clocks put in phy driver are not >>> enabled. >> >> it seems like the same clock is needed by PHY and XHCI. This patch looks >> incorrect. > > > Hi, > > I agree that the driver should enable clock it used by itself and not > depends on init order. This should be fixed. > > But in general, I think it make sense to only add hcd after all required > resource are ready. At least it remove unnecessary calls to > usb_add_hcd/usb_remove_hcd. Is it better if the commit message is > changed to something like the below? > > Currently xhci_plat_probe() call usb_add_hcd before trying to init the > phy. However if the phy is not ready at the moment, it have to remove > the hcd and probe again later > > Change the init order so we only add hcd when all required resource are > ready. > Hi Rogers Quadros patchseries that changes how HCDs are created and added for xhci-plat was just sent forward. It first creates both HCDs, then adds them. Doesn't usb_add_hcd() as it's first task take care of the PHYs? I'm hoping to remove that part completely from xhci-plat.c but haven't looked into it properly yet. -Mathias
Mathias. On 01/06/15 18:17, Mathias Nyman wrote: > On 01.06.2015 17:52, Yingjoe Chen wrote: >> On Wed, 2015-05-27 at 07:18 -0500, Felipe Balbi wrote: >>> On Wed, May 27, 2015 at 07:48:00PM +0800, chunfeng.yun@mediatek.com wrote: >>>> From: Chunfeng Yun <chunfeng.yun@mediatek.com> >>>> >>>> find the phy driver before add primary usb_hcd to avoid acessing >>>> xHCI register which may hangup the system when the phy is not loaded >>>> yet and the related powers or clocks put in phy driver are not >>>> enabled. >>> >>> it seems like the same clock is needed by PHY and XHCI. This patch looks >>> incorrect. >> >> >> Hi, >> >> I agree that the driver should enable clock it used by itself and not >> depends on init order. This should be fixed. >> >> But in general, I think it make sense to only add hcd after all required >> resource are ready. At least it remove unnecessary calls to >> usb_add_hcd/usb_remove_hcd. Is it better if the commit message is >> changed to something like the below? >> >> Currently xhci_plat_probe() call usb_add_hcd before trying to init the >> phy. However if the phy is not ready at the moment, it have to remove >> the hcd and probe again later >> >> Change the init order so we only add hcd when all required resource are >> ready. >> > Hi > > Rogers Quadros patchseries that changes how HCDs are created and added for > xhci-plat was just sent forward. It first creates both HCDs, then adds them. > > Doesn't usb_add_hcd() as it's first task take care of the PHYs? > I'm hoping to remove that part completely from xhci-plat.c but haven't > looked into it properly yet. > usb_add_hcd() does if (IS_ENABLED(CONFIG_USB_PHY) && !hcd->usb_phy) { struct usb_phy *phy = usb_get_phy_dev(hcd->self.controller, 0); ... if (IS_ENABLED(CONFIG_GENERIC_PHY) && !hcd->phy) { struct phy *phy = phy_get(hcd->self.controller, "usb"); ... but xhci-plat.c does hcd->usb_phy = devm_usb_get_phy_by_phandle(&pdev->dev, "usb-phy", 0); So there needs to be some alignment. cheers, -roger
diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c index 783e819..c10f5fa 100644 --- a/drivers/usb/host/xhci-plat.c +++ b/drivers/usb/host/xhci-plat.c @@ -127,9 +127,21 @@ static int xhci_plat_probe(struct platform_device *pdev) goto disable_clk; } + hcd->usb_phy = devm_usb_get_phy_by_phandle(&pdev->dev, "usb-phy", 0); + if (IS_ERR(hcd->usb_phy)) { + ret = PTR_ERR(hcd->usb_phy); + if (ret == -EPROBE_DEFER) + goto disable_clk; + hcd->usb_phy = NULL; + } else { + ret = usb_phy_init(hcd->usb_phy); + if (ret) + goto disable_clk; + } + ret = usb_add_hcd(hcd, irq, IRQF_SHARED); if (ret) - goto disable_clk; + goto disable_usb_phy; device_wakeup_enable(hcd->self.controller); @@ -156,33 +168,21 @@ static int xhci_plat_probe(struct platform_device *pdev) if (HCC_MAX_PSA(xhci->hcc_params) >= 4) xhci->shared_hcd->can_do_streams = 1; - hcd->usb_phy = devm_usb_get_phy_by_phandle(&pdev->dev, "usb-phy", 0); - if (IS_ERR(hcd->usb_phy)) { - ret = PTR_ERR(hcd->usb_phy); - if (ret == -EPROBE_DEFER) - goto put_usb3_hcd; - hcd->usb_phy = NULL; - } else { - ret = usb_phy_init(hcd->usb_phy); - if (ret) - goto put_usb3_hcd; - } - ret = usb_add_hcd(xhci->shared_hcd, irq, IRQF_SHARED); if (ret) - goto disable_usb_phy; + goto put_usb3_hcd; return 0; -disable_usb_phy: - usb_phy_shutdown(hcd->usb_phy); - put_usb3_hcd: usb_put_hcd(xhci->shared_hcd); dealloc_usb2_hcd: usb_remove_hcd(hcd); +disable_usb_phy: + usb_phy_shutdown(hcd->usb_phy); + disable_clk: if (!IS_ERR(clk)) clk_disable_unprepare(clk);