| From 2c77e264a0186790c1fa137be76b61e3f00a6321 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Fri, 11 Sep 2020 09:25:11 +1200 |
| Subject: usb: ohci: Default to per-port over-current protection |
| |
| From: Hamish Martin <hamish.martin@alliedtelesis.co.nz> |
| |
| [ Upstream commit b77d2a0a223bc139ee8904991b2922d215d02636 ] |
| |
| Some integrated OHCI controller hubs do not expose all ports of the hub |
| to pins on the SoC. In some cases the unconnected ports generate |
| spurious over-current events. For example the Broadcom 56060/Ranger 2 SoC |
| contains a nominally 3 port hub but only the first port is wired. |
| |
| Default behaviour for ohci-platform driver is to use global over-current |
| protection mode (AKA "ganged"). This leads to the spurious over-current |
| events affecting all ports in the hub. |
| |
| We now alter the default to use per-port over-current protection. |
| |
| This patch results in the following configuration changes depending |
| on quirks: |
| - For quirk OHCI_QUIRK_SUPERIO no changes. These systems remain set up |
| for ganged power switching and no over-current protection. |
| - For quirk OHCI_QUIRK_AMD756 or OHCI_QUIRK_HUB_POWER power switching |
| remains at none, while over-current protection is now guaranteed to be |
| set to per-port rather than the previous behaviour where it was either |
| none or global over-current protection depending on the value at |
| function entry. |
| |
| Suggested-by: Alan Stern <stern@rowland.harvard.edu> |
| Acked-by: Alan Stern <stern@rowland.harvard.edu> |
| Signed-off-by: Hamish Martin <hamish.martin@alliedtelesis.co.nz> |
| Link: https://lore.kernel.org/r/20200910212512.16670-1-hamish.martin@alliedtelesis.co.nz |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/usb/host/ohci-hcd.c | 16 ++++++++++------ |
| 1 file changed, 10 insertions(+), 6 deletions(-) |
| |
| diff --git a/drivers/usb/host/ohci-hcd.c b/drivers/usb/host/ohci-hcd.c |
| index dd37e77dae001..2845ea328a064 100644 |
| --- a/drivers/usb/host/ohci-hcd.c |
| +++ b/drivers/usb/host/ohci-hcd.c |
| @@ -673,20 +673,24 @@ static int ohci_run (struct ohci_hcd *ohci) |
| |
| /* handle root hub init quirks ... */ |
| val = roothub_a (ohci); |
| - val &= ~(RH_A_PSM | RH_A_OCPM); |
| + /* Configure for per-port over-current protection by default */ |
| + val &= ~RH_A_NOCP; |
| + val |= RH_A_OCPM; |
| if (ohci->flags & OHCI_QUIRK_SUPERIO) { |
| - /* NSC 87560 and maybe others */ |
| + /* NSC 87560 and maybe others. |
| + * Ganged power switching, no over-current protection. |
| + */ |
| val |= RH_A_NOCP; |
| - val &= ~(RH_A_POTPGT | RH_A_NPS); |
| - ohci_writel (ohci, val, &ohci->regs->roothub.a); |
| + val &= ~(RH_A_POTPGT | RH_A_NPS | RH_A_PSM | RH_A_OCPM); |
| } else if ((ohci->flags & OHCI_QUIRK_AMD756) || |
| (ohci->flags & OHCI_QUIRK_HUB_POWER)) { |
| /* hub power always on; required for AMD-756 and some |
| - * Mac platforms. ganged overcurrent reporting, if any. |
| + * Mac platforms. |
| */ |
| val |= RH_A_NPS; |
| - ohci_writel (ohci, val, &ohci->regs->roothub.a); |
| } |
| + ohci_writel(ohci, val, &ohci->regs->roothub.a); |
| + |
| ohci_writel (ohci, RH_HS_LPSC, &ohci->regs->roothub.status); |
| ohci_writel (ohci, (val & RH_A_NPS) ? 0 : RH_B_PPCM, |
| &ohci->regs->roothub.b); |
| -- |
| 2.25.1 |
| |
