Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1265429

[PATCH v3 07/12] usb: xhci: dbc: handle dbc-configured exit

Show all headers | View raw

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

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH v3 00/12] usb: early: add support for early printk through USB3 debug port Lu Baolu <baolu.lu@linux.intel.com> - 2015-11-09 08:50 +0100
  [PATCH v3 11/12] usb: serial: usb_debug: add support for dbc debug device Lu Baolu <baolu.lu@linux.intel.com> - 2015-11-09 08:50 +0100
  [PATCH v3 09/12] x86: early_printk: add USB3 debug port earlyprintk support Lu Baolu <baolu.lu@linux.intel.com> - 2015-11-09 08:50 +0100
  [PATCH v3 04/12] usb: xhci: dbc: add support for Intel xHCI dbc quirk Lu Baolu <baolu.lu@linux.intel.com> - 2015-11-09 08:50 +0100
  [PATCH v3 02/12] x86: fixmap: add permanent fixmap for xhci debug port Lu Baolu <baolu.lu@linux.intel.com> - 2015-11-09 08:50 +0100
  [PATCH v3 10/12] usb: xhci: dbc: add handshake between debug target and host Lu Baolu <baolu.lu@linux.intel.com> - 2015-11-09 08:50 +0100
  [PATCH v3 07/12] usb: xhci: dbc: handle dbc-configured exit Lu Baolu <baolu.lu@linux.intel.com> - 2015-11-09 08:50 +0100
  [PATCH v3 01/12] usb: xhci: add sysfs file for xHCI debug port Lu Baolu <baolu.lu@linux.intel.com> - 2015-11-09 08:50 +0100
    Re: [PATCH v3 01/12] usb: xhci: add sysfs file for xHCI debug port Dave Young <dyoung@redhat.com> - 2015-11-10 10:40 +0100
      Re: [PATCH v3 01/12] usb: xhci: add sysfs file for xHCI debug port "Lu, Baolu" <baolu.lu@linux.intel.com> - 2015-11-11 03:10 +0100
  Re: [PATCH v3 00/12] usb: early: add support for early printk  through USB3 debug port Dave Young <dyoung@redhat.com> - 2015-11-10 10:50 +0100
    Re: [PATCH v3 00/12] usb: early: add support for early printk through  USB3 debug port "Lu, Baolu" <baolu.lu@linux.intel.com> - 2015-11-11 02:40 +0100
      Re: [PATCH v3 00/12] usb: early: add support for early printk  through USB3 debug port Dave Young <dyoung@redhat.com> - 2015-11-11 03:30 +0100
        Re: [PATCH v3 00/12] usb: early: add support for early printk through  USB3 debug port "Lu, Baolu" <baolu.lu@linux.intel.com> - 2015-11-11 03:50 +0100
        Re: [PATCH v3 00/12] usb: early: add support for early printk through  USB3 debug port "Lu, Baolu" <baolu.lu@linux.intel.com> - 2015-11-11 07:00 +0100
        Re: [PATCH v3 00/12] usb: early: add support for early printk through  USB3 debug port "Lu, Baolu" <baolu.lu@linux.intel.com> - 2015-11-12 03:50 +0100
          Re: [PATCH v3 00/12] usb: early: add support for early printk  through USB3 debug port Dave Young <dyoung@redhat.com> - 2015-11-12 07:10 +0100
            Re: [PATCH v3 00/12] usb: early: add support for early printk through  USB3 debug port "Lu, Baolu" <baolu.lu@linux.intel.com> - 2015-11-13 03:10 +0100
              Re: [PATCH v3 00/12] usb: early: add support for early printk  through USB3 debug port Dave Young <dyoung@redhat.com> - 2015-11-13 03:30 +0100
                Re: [PATCH v3 00/12] usb: early: add support for early printk through  USB3 debug port Lu Baolu <baolu.lu@linux.intel.com> - 2015-11-13 07:30 +0100

csiph-web