From 93f1a47c4af34c4ee014b3d2aae70089b3b69f72 Mon Sep 17 00:00:00 2001 From: David Brownell Date: Thu, 16 Nov 2006 23:34:58 -0800 Subject: [PATCH] USB: add ehci_hcd.ignore_oc parameter Certain boards seem to like to issue false overcurrent notifications, for example on ports that don't have anything connected to them. This looks like a hardware error, at the level of noise to those ports' overcurrent input signals (or non-debounced VBUS comparators). This surfaces to users as truly massive amounts of syslog spam from khubd (which is appropriate for real hardware problems, except for the volume from multiple ports). Using this new "ignore_oc" flag helps such systems work more sanely, by preventing such indications from getting to khubd (and spam syslog). The downside is of course that true overcurrent errors will be masked; they'll appear as spontaneous disconnects, without the diagnostics that will let users troubleshoot issues like short circuited cables. Note that the bulk of these reports seem to be with VIA southbridges, but I think some were with Intel ones. Signed-off-by: David Brownell Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/ehci-hcd.c | 10 ++++++++-- drivers/usb/host/ehci-hub.c | 18 +++++++++++++++--- 2 files changed, 23 insertions(+), 5 deletions(-) diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c index 9030994aba9..f2ceb5fdbeb 100644 --- a/drivers/usb/host/ehci-hcd.c +++ b/drivers/usb/host/ehci-hcd.c @@ -126,6 +126,11 @@ static unsigned park = 0; module_param (park, uint, S_IRUGO); MODULE_PARM_DESC (park, "park setting; 1-3 back-to-back async packets"); +/* for flakey hardware, ignore overcurrent indicators */ +static int ignore_oc = 0; +module_param (ignore_oc, bool, S_IRUGO); +MODULE_PARM_DESC (ignore_oc, "ignore bogus hardware overcurrent indications"); + #define INTR_MASK (STS_IAA | STS_FATAL | STS_PCD | STS_ERR | STS_INT) /*-------------------------------------------------------------------------*/ @@ -541,9 +546,10 @@ static int ehci_run (struct usb_hcd *hcd) temp = HC_VERSION(readl (&ehci->caps->hc_capbase)); ehci_info (ehci, - "USB %x.%x started, EHCI %x.%02x, driver %s\n", + "USB %x.%x started, EHCI %x.%02x, driver %s%s\n", ((ehci->sbrn & 0xf0)>>4), (ehci->sbrn & 0x0f), - temp >> 8, temp & 0xff, DRIVER_VERSION); + temp >> 8, temp & 0xff, DRIVER_VERSION, + ignore_oc ? ", overcurrent ignored" : ""); writel (INTR_MASK, &ehci->regs->intr_enable); /* Turn On Interrupts */ diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c index 7c170a29f95..0a56dfa2745 100644 --- a/drivers/usb/host/ehci-hub.c +++ b/drivers/usb/host/ehci-hub.c @@ -218,6 +218,7 @@ ehci_hub_status_data (struct usb_hcd *hcd, char *buf) { struct ehci_hcd *ehci = hcd_to_ehci (hcd); u32 temp, status = 0; + u32 mask; int ports, i, retval = 1; unsigned long flags; @@ -233,6 +234,18 @@ ehci_hub_status_data (struct usb_hcd *hcd, char *buf) retval++; } + /* Some boards (mostly VIA?) report bogus overcurrent indications, + * causing massive log spam unless we completely ignore them. It + * may be relevant that VIA VT8235 controlers, where PORT_POWER is + * always set, seem to clear PORT_OCC and PORT_CSC when writing to + * PORT_POWER; that's surprising, but maybe within-spec. + */ + if (!ignore_oc) + mask = PORT_CSC | PORT_PEC | PORT_OCC; + else + mask = PORT_CSC | PORT_PEC; + // PORT_RESUME from hardware ~= PORT_STAT_C_SUSPEND + /* no hub change reports (bit 0) for now (power, ...) */ /* port N changes (bit N)? */ @@ -250,8 +263,7 @@ ehci_hub_status_data (struct usb_hcd *hcd, char *buf) } if (!(temp & PORT_CONNECT)) ehci->reset_done [i] = 0; - if ((temp & (PORT_CSC | PORT_PEC | PORT_OCC)) != 0 - // PORT_STAT_C_SUSPEND? + if ((temp & mask) != 0 || ((temp & PORT_RESUME) != 0 && time_after (jiffies, ehci->reset_done [i]))) { @@ -418,7 +430,7 @@ static int ehci_hub_control ( status |= 1 << USB_PORT_FEAT_C_CONNECTION; if (temp & PORT_PEC) status |= 1 << USB_PORT_FEAT_C_ENABLE; - if (temp & PORT_OCC) + if ((temp & PORT_OCC) && !ignore_oc) status |= 1 << USB_PORT_FEAT_C_OVER_CURRENT; /* whoever resumes must GetPortStatus to complete it!! */ -- 2.41.1