diff options
| author | Oliver Neukum <oliver@neukum.org> | 2009-11-27 15:17:59 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2009-11-30 16:43:16 -0800 |
| commit | ee4ecb8ac63a5792bec448037d4b82ec4144f94b (patch) | |
| tree | b272d4c5bcfe8ef8e7c94b6182fa2b3ed024b745 | |
| parent | 8d6499e5bde91ad05dea4f666bdfe79e65e7cf96 (diff) | |
| download | linux-3.10-ee4ecb8ac63a5792bec448037d4b82ec4144f94b.tar.gz linux-3.10-ee4ecb8ac63a5792bec448037d4b82ec4144f94b.tar.bz2 linux-3.10-ee4ecb8ac63a5792bec448037d4b82ec4144f94b.zip | |
USB: work around for EHCI with quirky periodic schedules
a quirky chipset needs periodic schedules to run for a minimum
time before they can be disabled again. This enforces the requirement
with a time stamp and a calculated delay
Signed-off-by: Oliver Neukum <oliver@neukum.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | drivers/usb/host/ehci-hcd.c | 2 | ||||
| -rw-r--r-- | drivers/usb/host/ehci-pci.c | 4 | ||||
| -rw-r--r-- | drivers/usb/host/ehci-sched.c | 12 | ||||
| -rw-r--r-- | drivers/usb/host/ehci.h | 2 |
4 files changed, 20 insertions, 0 deletions
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c index 9835e071394..f5f5601701c 100644 --- a/drivers/usb/host/ehci-hcd.c +++ b/drivers/usb/host/ehci-hcd.c @@ -28,6 +28,7 @@ #include <linux/errno.h> #include <linux/init.h> #include <linux/timer.h> +#include <linux/ktime.h> #include <linux/list.h> #include <linux/interrupt.h> #include <linux/usb.h> @@ -676,6 +677,7 @@ static int ehci_run (struct usb_hcd *hcd) ehci_readl(ehci, &ehci->regs->command); /* unblock posted writes */ msleep(5); up_write(&ehci_cf_port_reset_rwsem); + ehci->last_periodic_enable = ktime_get_real(); temp = HC_VERSION(ehci_readl(ehci, &ehci->caps->hc_capbase)); ehci_info (ehci, diff --git a/drivers/usb/host/ehci-pci.c b/drivers/usb/host/ehci-pci.c index 378861b9d79..ead5f4f2aa5 100644 --- a/drivers/usb/host/ehci-pci.c +++ b/drivers/usb/host/ehci-pci.c @@ -111,6 +111,10 @@ static int ehci_pci_setup(struct usb_hcd *hcd) switch (pdev->vendor) { case PCI_VENDOR_ID_INTEL: ehci->need_io_watchdog = 0; + if (pdev->device == 0x27cc) { + ehci->broken_periodic = 1; + ehci_info(ehci, "using broken periodic workaround\n"); + } break; case PCI_VENDOR_ID_TDI: if (pdev->device == PCI_DEVICE_ID_TDI_EHCI) { diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c index b25cdea93a1..a5535b5e3fe 100644 --- a/drivers/usb/host/ehci-sched.c +++ b/drivers/usb/host/ehci-sched.c @@ -475,6 +475,8 @@ static int enable_periodic (struct ehci_hcd *ehci) /* make sure ehci_work scans these */ ehci->next_uframe = ehci_readl(ehci, &ehci->regs->frame_index) % (ehci->periodic_size << 3); + if (unlikely(ehci->broken_periodic)) + ehci->last_periodic_enable = ktime_get_real(); return 0; } @@ -486,6 +488,16 @@ static int disable_periodic (struct ehci_hcd *ehci) if (--ehci->periodic_sched) return 0; + if (unlikely(ehci->broken_periodic)) { + /* delay experimentally determined */ + ktime_t safe = ktime_add_us(ehci->last_periodic_enable, 1000); + ktime_t now = ktime_get_real(); + s64 delay = ktime_us_delta(safe, now); + + if (unlikely(delay > 0)) + udelay(delay); + } + /* did setting PSE not take effect yet? * takes effect only at frame boundaries... */ diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h index 064e76821ff..2d85e21ff28 100644 --- a/drivers/usb/host/ehci.h +++ b/drivers/usb/host/ehci.h @@ -118,6 +118,7 @@ struct ehci_hcd { /* one per controller */ unsigned stamp; unsigned random_frame; unsigned long next_statechange; + ktime_t last_periodic_enable; u32 command; /* SILICON QUIRKS */ @@ -127,6 +128,7 @@ struct ehci_hcd { /* one per controller */ unsigned big_endian_desc:1; unsigned has_amcc_usb23:1; unsigned need_io_watchdog:1; + unsigned broken_periodic:1; /* required for usb32 quirk */ #define OHCI_CTRL_HCFS (3 << 6) |