From: Orjan Friberg <of@flatfrog.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH] MUSB timeout broken
Date: Mon, 4 Jul 2011 16:37:34 +0200 [thread overview]
Message-ID: <4E11D02E.7030803@flatfrog.com> (raw)
The following construct (musb_hcd.c, usb_lowlevel_init)
timeout = musb_cfg.timeout;
while (timeout--)
if (readb(&musbr->devctl) & MUSB_DEVCTL_HM)
break;
will leave timeout == -1 when the timeout is reached, hence the timeout
detecting code that follows will not trigger:
/* if musb core is not in host mode, then return */
if (!timeout)
return -1;
Without the patch below, doing a 'usb reset' without a device connected
makes it impossible to discover connected devices later. I have not
investigated why this happens since the timeout logic was broken (and
correcting that fixed the issue at hand).
Changed to pre-decrement since I assume the timeout value is not *that*
exact.
Thanks,
Orjan
diff --git a/drivers/usb/musb/musb_hcd.c b/drivers/usb/musb/musb_hcd.c
index 974bb31..adcf7f7 100644
--- a/drivers/usb/musb/musb_hcd.c
+++ b/drivers/usb/musb/musb_hcd.c
@@ -1114,7 +1114,7 @@ int usb_lowlevel_init(void)
* should be a usb device connected.
*/
timeout = musb_cfg.timeout;
- while (timeout--)
+ while (--timeout)
if (readb(&musbr->devctl) & MUSB_DEVCTL_HM)
break;
--
Orjan Friberg
FlatFrog Laboratories AB
next reply other threads:[~2011-07-04 14:37 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-04 14:37 Orjan Friberg [this message]
2011-07-04 15:07 ` [U-Boot] [PATCH] MUSB timeout broken Wolfgang Denk
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