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... 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);