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authorThang Q. Nguyen <tqnguyen@apm.com>2017-10-05 11:21:37 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-10-05 11:01:57 +0200
commit4750bc78efdb126ddc40f1b34dbae7ce319344cb (patch)
treee8beed27b739a1fafe3736d47b579c173f26dd2a /drivers/usb/host
parentfb9bbce6e67a2c33a1902380b1c3d3d96e75af52 (diff)
usb: host: xhci support option to disable the xHCI USB2 HW LPM
XHCI specification 1.1 does not require xHCI-compliant controllers to always enable hardware USB2 LPM. However, the current xHCI driver always enable it when seeing HLC=1. This patch supports an option for users to control disabling USB2 Hardware LPM via DT/ACPI attribute. This option is needed in case user would like to disable this feature. For example, their xHCI controller has its USB2 HW LPM broken. Signed-off-by: Tung Nguyen <tunguyen@apm.com> Signed-off-by: Thang Q. Nguyen <tqnguyen@apm.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/host')
-rw-r--r--drivers/usb/host/xhci-plat.c3
-rw-r--r--drivers/usb/host/xhci.c2
-rw-r--r--drivers/usb/host/xhci.h1
3 files changed, 5 insertions, 1 deletions
diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index 163bafde709f..d0625faee8f7 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -259,6 +259,9 @@ static int xhci_plat_probe(struct platform_device *pdev)
goto disable_clk;
}
+ if (device_property_read_bool(sysdev, "usb2-lpm-disable"))
+ xhci->quirks |= XHCI_HW_LPM_DISABLE;
+
if (device_property_read_bool(sysdev, "usb3-lpm-capable"))
xhci->quirks |= XHCI_LPM_SUPPORT;
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index b2ff1ff1a02f..3a8e75f6898f 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -4087,7 +4087,7 @@ static int xhci_set_usb2_hardware_lpm(struct usb_hcd *hcd,
xhci_dbg(xhci, "%s port %d USB2 hardware LPM\n",
enable ? "enable" : "disable", port_num + 1);
- if (enable) {
+ if (enable && !(xhci->quirks & XHCI_HW_LPM_DISABLE)) {
/* Host supports BESL timeout instead of HIRD */
if (udev->usb2_hw_lpm_besl_capable) {
/* if device doesn't have a preferred BESL value use a
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 2abaa4d6d39d..dc22392711e3 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1828,6 +1828,7 @@ struct xhci_hcd {
#define XHCI_LIMIT_ENDPOINT_INTERVAL_7 (1 << 26)
#define XHCI_U2_DISABLE_WAKE (1 << 27)
#define XHCI_ASMEDIA_MODIFY_FLOWCONTROL (1 << 28)
+#define XHCI_HW_LPM_DISABLE (1 << 29)
unsigned int num_active_eps;
unsigned int limit_active_eps;