From: Roger Quadros <rogerq@ti.com>
To: <mathias.nyman@intel.com>
Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>,
<linux-usb@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
<rogerq@ti.com>
Subject: [PATCH v3] usb: xhci: bInterval quirk for TI TUSB73x0
Date: Wed, 22 Mar 2017 13:43:56 +0200 [thread overview]
Message-ID: <787d6f0f-d69c-ba4a-8892-b3558c005184@ti.com> (raw)
In-Reply-To: <9de96f48-1570-974a-2ceb-acf051a80e6b@ti.com>
As per [1] issue #4,
"The periodic EP scheduler always tries to schedule the EPs
that have large intervals (interval equal to or greater than
128 microframes) into different microframes. So it maintains
an internal counter and increments for each large interval
EP added. When the counter is greater than 128, the scheduler
rejects the new EP. So when the hub re-enumerated 128 times,
it triggers this condition."
This results in Bandwidth error when devices with periodic
endpoints (ISO/INT) having bInterval > 7 are plugged and
unplugged several times on a TUSB73x0 XHCI host.
Workaround this issue by limiting the bInterval to 7
(i.e. interval to 6) for High-speed or faster periodic endpoints.
[1] - http://www.ti.com/lit/er/sllz076/sllz076.pdf
Signed-off-by: Roger Quadros <rogerq@ti.com>
---
v3:
-fixed some more typos in commit message
v2:
-fixed typo in commit message
drivers/usb/host/xhci-mem.c | 11 +++++++++++
drivers/usb/host/xhci-pci.c | 3 +++
drivers/usb/host/xhci.h | 1 +
3 files changed, 15 insertions(+)
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index ba1853f4..05fb3f6 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -1502,6 +1502,17 @@ int xhci_endpoint_init(struct xhci_hcd *xhci,
*/
max_esit_payload = xhci_get_max_esit_payload(udev, ep);
interval = xhci_get_endpoint_interval(udev, ep);
+
+ /* Periodic endpoint bInterval limit quirk */
+ if (usb_endpoint_xfer_int(&ep->desc) ||
+ usb_endpoint_xfer_isoc(&ep->desc)) {
+ if ((xhci->quirks & XHCI_LIMIT_ENDPOINT_INTERVAL_7) &&
+ udev->speed >= USB_SPEED_HIGH &&
+ interval >= 7) {
+ interval = 6;
+ }
+ }
+
mult = xhci_get_endpoint_mult(udev, ep);
max_packet = usb_endpoint_maxp(&ep->desc);
max_burst = xhci_get_endpoint_max_burst(udev, ep);
diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index fc99f51..7b86508 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -199,6 +199,9 @@ static void xhci_pci_quirks(struct device *dev, struct xhci_hcd *xhci)
pdev->device == 0x1042)
xhci->quirks |= XHCI_BROKEN_STREAMS;
+ if (pdev->vendor == PCI_VENDOR_ID_TI && pdev->device == 0x8241)
+ xhci->quirks |= XHCI_LIMIT_ENDPOINT_INTERVAL_7;
+
if (xhci->quirks & XHCI_RESET_ON_RESUME)
xhci_dbg_trace(xhci, trace_xhci_dbg_quirks,
"QUIRK: Resetting on resume");
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index da3eb69..2496bd6 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1818,6 +1818,7 @@ struct xhci_hcd {
#define XHCI_MISSING_CAS (1 << 24)
/* For controller with a broken Port Disable implementation */
#define XHCI_BROKEN_PORT_PED (1 << 25)
+#define XHCI_LIMIT_ENDPOINT_INTERVAL_7 (1 << 26)
unsigned int num_active_eps;
unsigned int limit_active_eps;
--
2.7.4
next prev parent reply other threads:[~2017-03-22 11:44 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-09 8:47 [PATCH] usb: xhci: bInterval quirk for TI TUSB73x0 Roger Quadros
2017-03-09 9:44 ` Sergei Shtylyov
2017-03-10 16:04 ` Roger Quadros
2017-03-13 8:11 ` [PATCH v2] " Roger Quadros
2017-03-13 8:44 ` Sergei Shtylyov
2017-03-22 11:43 ` Roger Quadros [this message]
2017-03-22 13:06 ` [PATCH v3] " Mathias Nyman
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