[PATCH 1/5] xhci: Use correct SLOT ID when handling a reset device command

[PATCH 1/5] xhci: Use correct SLOT ID when handling a reset device command

[Mathias Nyman]

Command completion events normally include command completion status,
SLOT_ID, and a pointer to the original command. Reset device command
completion SLOT_ID may be zero according to xhci specs 4.6.11.

VIA controllers set the SLOT_ID to zero, triggering a WARN_ON in the
command completion handler.

Use the SLOT ID found from the original command instead.

This patch should be applied to stable kernels since 3.13 that contain
the commit 20e7acb13ff48fbc884d5918c3697c27de63922a
"xhci: use completion event's slot id rather than dig it out of command"

Cc: stable@vger.kernel.org # 3.13
Reported-by: Saran Neti <sarannmr@gmail.com>
Tested-by: Saran Neti <sarannmr@gmail.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
---
 drivers/usb/host/xhci-ring.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index d67ff71..71657d3 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1433,8 +1433,11 @@ static void handle_cmd_completion(struct xhci_hcd *xhci,
 		xhci_handle_cmd_reset_ep(xhci, slot_id, cmd_trb, cmd_comp_code);
 		break;
 	case TRB_RESET_DEV:
-		WARN_ON(slot_id != TRB_TO_SLOT_ID(
-				le32_to_cpu(cmd_trb->generic.field[3])));
+		/* SLOT_ID field in reset device cmd completion event TRB is 0.
+		 * Use the SLOT_ID from the command TRB instead (xhci 4.6.11)
+		 */
+		slot_id = TRB_TO_SLOT_ID(
+				le32_to_cpu(cmd_trb->generic.field[3]));
 		xhci_handle_cmd_reset_dev(xhci, slot_id, event);
 		break;
 	case TRB_NEC_GET_FW:
-- 
1.8.3.2

RE: [PATCH 1/5] xhci: Use correct SLOT ID when handling a reset device command

[David Laight]

From: Of Mathias Nyman
> Command completion events normally include command completion status,
> SLOT_ID, and a pointer to the original command. Reset device command
> completion SLOT_ID may be zero according to xhci specs 4.6.11.
> 
> VIA controllers set the SLOT_ID to zero, triggering a WARN_ON in the
> command completion handler.
> 
> Use the SLOT ID found from the original command instead.
> 
> This patch should be applied to stable kernels since 3.13 that contain
> the commit 20e7acb13ff48fbc884d5918c3697c27de63922a
> "xhci: use completion event's slot id rather than dig it out of command"
> 
> Cc: stable@vger.kernel.org # 3.13
> Reported-by: Saran Neti <sarannmr@gmail.com>
> Tested-by: Saran Neti <sarannmr@gmail.com>
> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
> ---
>  drivers/usb/host/xhci-ring.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
> index d67ff71..71657d3 100644
> --- a/drivers/usb/host/xhci-ring.c
> +++ b/drivers/usb/host/xhci-ring.c
> @@ -1433,8 +1433,11 @@ static void handle_cmd_completion(struct xhci_hcd *xhci,
>  		xhci_handle_cmd_reset_ep(xhci, slot_id, cmd_trb, cmd_comp_code);
>  		break;
>  	case TRB_RESET_DEV:
> -		WARN_ON(slot_id != TRB_TO_SLOT_ID(
> -				le32_to_cpu(cmd_trb->generic.field[3])));
> +		/* SLOT_ID field in reset device cmd completion event TRB is 0.

Minor nit...
Surely is would be better to say 'is undefined' or 'may be zero'.

	David

[PATCH 2/5] xhci: correct burst count field for isoc transfers on 1.0 xhci hosts

[Mathias Nyman]

The transfer burst count (TBC) field in xhci 1.0 hosts should be set
to the number of bursts needed to transfer all packets in a isoc TD.
Supported values are 0-2 (1 to 3 bursts per service interval).

Formula for TBC calculation is given in xhci spec section 4.11.2.3:
TBC = roundup( Transfer Descriptor Packet Count / Max Burst Size +1 ) - 1

This patch should be applied to stable kernels since 3.0 that contain
the commit 5cd43e33b9519143f06f507dd7cbee6b7a621885
"xhci 1.0: Set transfer burst count field."

Cc: stable@vger.kernel.org # 3.0
Suggested-by: ShiChun Ma <masc2008@qq.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
---
 drivers/usb/host/xhci-ring.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 71657d3..749fc68 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -3537,7 +3537,7 @@ static unsigned int xhci_get_burst_count(struct xhci_hcd *xhci,
 		return 0;
 
 	max_burst = urb->ep->ss_ep_comp.bMaxBurst;
-	return roundup(total_packet_count, max_burst + 1) - 1;
+	return DIV_ROUND_UP(total_packet_count, max_burst + 1) - 1;
 }
 
 /*
-- 
1.8.3.2

[PATCH 4/5] xhci: clear root port wake on bits if controller isn't wake-up capable

[Mathias Nyman]

From: Lu Baolu <baolu.lu@linux.intel.com>

When xHCI PCI host is suspended, if do_wakeup is false in xhci_pci_suspend,
xhci_bus_suspend needs to clear all root port wake on bits. Otherwise some Intel
platforms may get a spurious wakeup, even if PCI PME# is disabled.

This patch should be back-ported to kernels as old as 2.6.37, that
contains the commit 9777e3ce907d4cb5a513902a87ecd03b52499569
"USB: xHCI: bus power management implementation".

Cc: stable@vger.kernel.org # 2.6.37
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
---
 drivers/usb/host/xhci-hub.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index 2b998c6..aa79e87 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -22,6 +22,7 @@
 
 
 #include <linux/slab.h>
+#include <linux/device.h>
 #include <asm/unaligned.h>
 
 #include "xhci.h"
@@ -1139,7 +1140,9 @@ int xhci_bus_suspend(struct usb_hcd *hcd)
 		 * including the USB 3.0 roothub, but only if CONFIG_PM_RUNTIME
 		 * is enabled, so also enable remote wake here.
 		 */
-		if (hcd->self.root_hub->do_remote_wakeup) {
+		if (hcd->self.root_hub->do_remote_wakeup
+				&& device_may_wakeup(hcd->self.controller)) {
+
 			if (t1 & PORT_CONNECT) {
 				t2 |= PORT_WKOC_E | PORT_WKDISC_E;
 				t2 &= ~PORT_WKCONN_E;
-- 
1.8.3.2

[PATCH 5/5] xhci: Fix runtime suspended xhci from blocking system suspend.

[Mathias Nyman]

From: "Wang, Yu" <yu.y.wang@intel.com>

The system suspend flow as following:
1, Freeze all user processes and kenrel threads.

2, Try to suspend all devices.

2.1, If pci device is in RPM suspended state, then pci driver will try
to resume it to RPM active state in the prepare stage.

2.2, xhci_resume function calls usb_hcd_resume_root_hub to queue two
workqueue items to resume usb2&usb3 roothub devices.

2.3, Call suspend callbacks of devices.

2.3.1, All suspend callbacks of all hcd's children, including
roothub devices are called.

2.3.2, Finally, hcd_pci_suspend callback is called.

Due to workqueue threads were already frozen in step 1, the workqueue
items can't be scheduled, and the roothub devices can't be resumed in
this flow. The HCD_FLAG_WAKEUP_PENDING flag which is set in
usb_hcd_resume_root_hub won't be cleared. Finally,
hcd_pci_suspend will return -EBUSY, and system suspend fails.

The reason why this issue doesn't show up very often is due to that
choose_wakeup will be called in step 2.3.1. In step 2.3.1, if
udev->do_remote_wakeup is not equal to device_may_wakeup(&udev->dev), then
udev will resume to RPM active for changing the wakeup settings. This
has been a lucky hit which hides this issue.

For some special xHCI controllers which have no USB2 port, then roothub
will not match hub driver due to probe failed. Then its
do_remote_wakeup will be set to zero, and we won't be as lucky.

xhci driver doesn't need to resume roothub devices everytime like in
the above case. It's only needed when there are pending event TRBs.

This patch should be back-ported to kernels as old as 3.2, that
contains the commit f69e3120df82391a0ee8118e0a156239a06b2afb
"USB: XHCI: resume root hubs when the controller resumes"

Cc: stable@vger.kernel.org # 3.2
Signed-off-by: Wang, Yu <yu.y.wang@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
[use readl() instead of removed xhci_readl(), reword commit message -Mathias]
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
---
 drivers/usb/host/xhci.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 013aabb..f07be65 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -936,7 +936,7 @@ int xhci_suspend(struct xhci_hcd *xhci)
  */
 int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
 {
-	u32			command, temp = 0;
+	u32			command, temp = 0, status;
 	struct usb_hcd		*hcd = xhci_to_hcd(xhci);
 	struct usb_hcd		*secondary_hcd;
 	int			retval = 0;
@@ -1054,8 +1054,12 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
 
  done:
 	if (retval == 0) {
-		usb_hcd_resume_root_hub(hcd);
-		usb_hcd_resume_root_hub(xhci->shared_hcd);
+		/* Resume root hubs only when have pending events. */
+		status = readl(&xhci->op_regs->status);
+		if (status & STS_EINT) {
+			usb_hcd_resume_root_hub(hcd);
+			usb_hcd_resume_root_hub(xhci->shared_hcd);
+		}
 	}
 
 	/*
-- 
1.8.3.2