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小弟最近做了5块板子,用的创龙的核心板,其中4块USB2.0 host都没有问题,只有一块老是周期性报如下错误:0 V$ r/ u/ v0 p7 \2 }
hub 2-0:1.0: over-current condition on port 1
; x: p% p% i' h- P8 n, j1 M, b7 uda8xx_musb_interrupt 538: VBUS error workaround (delay coming)/ H9 w+ C- A1 T% `" A, x( N
我的电路图如附件,我用示波器测量过了,开始USB0_DRVVBUS脚起始是低电平,开机瞬间,它会变成高电平,USB0_VBUS也会) X) m4 {) h( t W
随着上升至5V,开机瞬间,USB0_VBUS并没有出现跌落至低于4.4V,从电路上没有发现问题,然后开始追踪linux3.3 USB驱动代码,$ O; z" F; }! K+ y4 l
发现,在da8xx_musb_interrupt函数中,有如下代码:
" b# A B4 {9 f, I1 x6 p( fif (status & (DA8XX_INTR_DRVVBUS << DA8XX_INTR_USB_SHIFT)) {
/ q% \/ S% Q& A9 t int drvvbus = musb_readl(reg_base, DA8XX_USB_STAT_REG);
/ A& k; r( b# c+ m) _ void __iomem *mregs = musb->mregs;% W* _ G n! F( t
u8 devctl = musb_readb(mregs, MUSB_DEVCTL);
r. x! K1 U! ` int err;
) T' }0 m- M: h* t9 d6 y/ d W
" q$ W" f: c. x* b U+ G err = is_host_enabled(musb) && (musb->int_usb &
7 n& s1 _! V. D9 n1 n" g' U MUSB_INTR_VBUSERROR);
q+ i, C; c1 [- ? u if (err) {
. l, w7 x2 ?3 V- W /*
; u$ ?) |& n- k5 n( c- ` * The Mentor core doesn't debounce VBUS as needed
* d( m z9 p& e5 q$ L# C/ D * 。。。
6 g% F9 w/ |* e' {" f2 G */8 J6 w+ f7 O$ @; W. o2 T z
musb->int_usb &= ~MUSB_INTR_VBUSERROR;
- z" g" D5 O+ z" V" U7 U& E* p. g1 P musb->xceiv->state = OTG_STATE_A_WAIT_VFALL;
# B: g$ Z. c: q4 | mod_timer(&otg_workaround, jiffies + POLL_SECONDS * HZ);( ~1 P7 C; L @0 W& _$ g7 }$ v
WARNING("VBUS error workaround (delay coming)\n");
! ~7 K7 Y/ J7 h7 k" |- D }
9 _. @) K6 A# @7 f
, y# \% T0 @, P8 \( j一直发生MUSB_INTR_VBUSERROR错误,然后会启动定时器,周期调用otg_timer函数,
5 i; @! H/ C. c% N跳入如下分支:6 E# O1 X' a5 ^$ B2 s3 J
devctl = musb_readb(mregs, MUSB_DEVCTL);( i0 L! T5 I6 F, q! X/ [5 t* c2 F
。。。& h- _4 R! S4 H+ K [* A0 h; I
case OTG_STATE_A_WAIT_VFALL:
6 D3 u, G8 ?. A6 ]! I3 l /*
: V2 g% b5 S) p * Wait till VBUS falls below SessionEnd (~0.2 V); the 1.3
2 f1 r G' f& X' ?. `+ r * RTL seems to mis-handle session "start" otherwise (or in
) Z; t/ L1 R' L+ D* t& ~ * our case "recover"), in routine "VBUS was valid by the time
" o: C+ l( X6 W! m2 q * VBUSERR got reported during enumeration" cases." ^) N$ k4 W- A( C7 O8 p
*/
7 J% J4 q& b: S" y0 `; j5 l: X if (devctl & MUSB_DEVCTL_VBUS) {1 c: n) H$ y) {2 A/ b! N
mod_timer(&otg_workaround, jiffies + POLL_SECONDS * HZ);
9 @+ a9 v4 ]9 L/ ~5 e3 z/ T# J break;
2 H8 Q, o1 J4 h% [- ? }, W( t `+ h6 e& R) n4 p6 s& V
musb->xceiv->state = OTG_STATE_A_WAIT_VRISE;
8 S& O! T x( y1 T7 k' ~ musb_writel(musb->ctrl_base, DA8XX_USB_INTR_SRC_SET_REG,
0 k) S! g z% }" a2 I) I* r MUSB_INTR_VBUSERROR << DA8XX_INTR_USB_SHIFT);
3 J: J5 u& I$ r2 Q5 w y3 |3 o& i4 E break;
! O& k7 T+ q: Q; W4 r% p
+ F6 w1 c0 B9 w$ H0 F3 u其中,devctl是设备控制寄存器,我打印了它的直,是0x80, 也就是位7是1,代表着是B device,,明明是A类," x5 z& b# T$ `9 k+ v. H% X. I
不知道为啥自动变成B类了。而且VBUS一直是5V,正常的啊,可是驱动也无法修复。。
_" Y4 I5 ]1 |, o 不知道亲们有没有遇到类似的情况,是怎么解决的?9 k6 M8 y# n- l0 a! A
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