[U-Boot] [PATCH] usb: Clear CMD_RUN while issuing CMD_RESET in ehci_reset()

Stefan Roese sr at denx.de
Fri Nov 26 15:44:00 CET 2010


This patch fixes a problem noticed on lwmon5 (PPC440EPx) using the
common EHCI driver, when "usb reset" is issued multiple times.
Upon the 2nd (and further) "usb reset" command, the command fails
with the following messages:

=> usb reset
(Re)start USB...
USB:   Register 1111 NbrPorts 1
USB EHCI 1.00
scanning bus for devices... 5 USB Device(s) found
       scanning bus for storage devices... 2 Storage Device(s) found
=> usb reset
(Re)start USB...
USB:   EHCI fail to reset
Error, couldn't init Lowlevel part

This patch fixes this problem. Now "usb reset" can be called multiple
times.

Signed-off-by: Stefan Roese <sr at denx.de>
Cc: Remy Bohmer <linux at bohmer.net>
---
 drivers/usb/host/ehci-hcd.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index b88488e..3c40a76 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -230,7 +230,7 @@ static int ehci_reset(void)
 	int ret = 0;
 
 	cmd = ehci_readl(&hcor->or_usbcmd);
-	cmd |= CMD_RESET;
+	cmd = (cmd & ~CMD_RUN) | CMD_RESET;
 	ehci_writel(&hcor->or_usbcmd, cmd);
 	ret = handshake((uint32_t *)&hcor->or_usbcmd, CMD_RESET, 0, 250 * 1000);
 	if (ret < 0) {
-- 
1.7.3.2



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