From: Sascha Hauer <s.hauer@pengutronix.de>
To: barebox@lists.infradead.org
Subject: [PATCH 2/4] USB ehci: speed up initialization
Date: Thu, 12 Apr 2012 21:40:03 +0200 [thread overview]
Message-ID: <1334259605-21907-3-git-send-email-s.hauer@pengutronix.de> (raw)
In-Reply-To: <1334259605-21907-1-git-send-email-s.hauer@pengutronix.de>
This is based on the following U-Boot commit:
commit 5f4b4f2fed3ab8590c8c06b78642f8c1467acacf
Author: Vincent Palatin <vpalatin@chromium.org>
Date: Mon Dec 5 14:52:22 2011 -0800
ehci: speed up initialization
According to EHCI specification v1.0, the controller should stabilize
the power on a port at most 20 ms after the port power bit transition.
So, we put this setting in the virtual descriptor corresponding field,
(bPwrOn2PwrGood = 10 => 10 x 2ms = 20ms), this saves about 500ms at each
controller initialization/enumeration.
Signed-off-by: Vincent Palatin <vpalatin@chromium.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
drivers/usb/core/usb.c | 2 +-
drivers/usb/host/ehci-hcd.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index 7039a2c..ba23e0e 100644
--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -934,8 +934,8 @@ static void usb_hub_power_on(struct usb_hub_device *hub)
for (i = 0; i < dev->maxchild; i++) {
usb_set_port_feature(dev, i + 1, USB_PORT_FEAT_POWER);
USB_HUB_PRINTF("port %d returns %lX\n", i + 1, dev->status);
- wait_ms(hub->desc.bPwrOn2PwrGood * 2);
}
+ mdelay(20);
}
#define MAX_TRIES 5
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 505d919..ae2b41e 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -64,7 +64,7 @@ static struct descriptor {
0x29, /* bDescriptorType: hub descriptor */
2, /* bNrPorts -- runtime modified */
0, /* wHubCharacteristics */
- 0xff, /* bPwrOn2PwrGood */
+ 10, /* bPwrOn2PwrGood */
0, /* bHubCntrCurrent */
{}, /* Device removable */
{} /* at most 7 ports! XXX */
--
1.7.10
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next prev parent reply other threads:[~2012-04-12 19:40 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-12 19:40 ehci patches Sascha Hauer
2012-04-12 19:40 ` [PATCH 1/4] USB ehci: make cache handling simpler Sascha Hauer
2012-04-12 19:40 ` Sascha Hauer [this message]
2012-04-12 19:40 ` [PATCH 3/4] ARM i.MX53: Setup USB clocks Sascha Hauer
2012-04-12 19:40 ` [PATCH 4/4] ARM i.MX53 LOCO: Add USB support Sascha Hauer
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