lkml.org 
[lkml]   [2015]   [Oct]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 07/12] usb: xhci: dbc: handle dbc-configured exit
Date
DbC might exit configured state in some cases (refer to 7.6.4.4 in
xHCI spec 1.1). Software needs detect and clear this situation by
clearing DCCTRL.DCR and wait until the DbC configured before read
or write oprations.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
drivers/usb/early/xhci-dbc.c | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)

diff --git a/drivers/usb/early/xhci-dbc.c b/drivers/usb/early/xhci-dbc.c
index f51daa4..8a5a51f 100644
--- a/drivers/usb/early/xhci-dbc.c
+++ b/drivers/usb/early/xhci-dbc.c
@@ -1153,6 +1153,29 @@ static int xdbc_wait_until_bulk_done(struct xdbc_trb *trb, int loops)
return -EIO;
}

+static int xdbc_wait_until_dbc_configured(void)
+{
+ int timeout = 0;
+ u32 reg;
+
+ /* Port exits configured state */
+ reg = readl(&xdbcp->xdbc_reg->control);
+ if (!(reg & CTRL_DRC))
+ return 0;
+
+ /* clear run change bit (RW1C) */
+ writel(reg | CTRL_DRC, &xdbcp->xdbc_reg->control);
+
+ do {
+ if (readl(&xdbcp->xdbc_reg->control) & CTRL_DCR)
+ return 0;
+
+ xdbc_udelay(10);
+ } while (timeout++ < XDBC_LOOPS);
+
+ return -ETIMEDOUT;
+}
+
static int xdbc_bulk_transfer(void *data, int size, int loops, bool read)
{
u64 addr;
@@ -1167,6 +1190,11 @@ static int xdbc_bulk_transfer(void *data, int size, int loops, bool read)
return -EINVAL;
}

+ if (xdbc_wait_until_dbc_configured()) {
+ xdbc_trace("%s: hardware not ready\n", __func__);
+ return -EPERM;
+ }
+
ring = (read ? &xdbcp->in_ring : &xdbcp->out_ring);
trb = ring->enqueue;
cycle = ring->cycle_state;
--
2.1.4


\
 
 \ /
  Last update: 2015-10-28 09:21    [W:0.208 / U:0.096 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site