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Re: [PATCH] Bluetooth: btusb: Restore QCA Rome suspend/resume fix with a "rewritten" version




Hi,

On 13-02-18 03:24, Brian Norris wrote:
Hi,

On Mon, Jan 08, 2018 at 10:44:16AM +0100, Hans de Goede wrote:
Commit 7d06d5895c15 ("Revert "Bluetooth: btusb: fix QCA...suspend/resume"")
removed the setting of the BTUSB_RESET_RESUME quirk for QCA Rome devices,
instead favoring adding USB_QUIRK_RESET_RESUME quirks in usb/core/quirks.c.

This was done because the DIY BTUSB_RESET_RESUME reset-resume handling
has several issues (see the original commit message). An added advantage
of moving over to the USB-core reset-resume handling is that it also
disables autosuspend for these devices, which is similarly broken on these.

Wait, is autosuspend actually broken for all QCA Rome chipsets? I don't
think so -- I'm using one now.

And have you manually enabled USB autosuspend for it, or are you
running something which might have done so, e.g. powertop --auto-tune ?

Because if you did not do that then you're already not using autosuspend
for your QCA devices and this patch will change nothing.

Thus, this is a poor solution, which
negatively affects my systems. However, I see that this patch was
applied regardless...

Note that there already is a quirk to handle broken suspend/resume
behavior on ALL QCA devices in older kernels. Also note that the
patches series which this commit builds on top of was already
setting USB_QUIRK_RESET_RESUME for some devices in
usb/core/quirks.c.

All my commit does is instead of duplicating all the QCA USB-ids in
usb/core/quirks.c, move the setting of USB_QUIRK_RESET_RESUME
to btusb.c so that we don't need to duplicate the USB-id tables.

The result of the combination of these patches is that the custom
DIY reset on resume handling btusb.c was doing is now replaced
by setting the standard USB-core USB_QUIRK_RESET_RESUME quirk.

As a (desirable) side effect this also disables USB autosuspend
for QCA devices since the USB-core does not allow USB autosuspend
on devices with the USB_QUIRK_RESET_RESUME quirk. Testing has shown
this to be necessary on at least some QCA devices and given that
these devices tend to loose there firmware on a suspend, it seems
sensible to not allow autosuspend on them.

> What justifications was found for this anyway? AIUI, this is a platform
> bug, and not entirely a chipset bug.

No this is believed to be a chipset issue, hence also the quirk in
older kernels to always reset these devices after a normal suspend/resume.

Regards,

Hans





Brian

But there are 2 issues with this approach:
1) It leaves the broken DIY BTUSB_RESET_RESUME code in place for Realtek
    devices.
2) Sofar only 2 of the 10 QCA devices known to the btusb code have been
    added to usb/core/quirks.c and if we fix the Realtek case the same way
    we need to add an additional 14 entries. So in essence we need to
    duplicate a large part of the usb_device_id table in btusb.c in
    usb/core/quirks.c and manually keep them in sync.

This commit instead restores setting a reset-resume quirk for QCA devices
in the btusb.c code, avoiding the duplicate usb_device_id table problem.

This commit avoids the problems with the original DIY BTUSB_RESET_RESUME
code by simply setting the USB_QUIRK_RESET_RESUME quirk directly on the
usb_device.

This commit also moves the BTUSB_REALTEK case over to directly setting the
USB_QUIRK_RESET_RESUME on the usb_device and removes the now unused
BTUSB_RESET_RESUME code.

BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1514836
Fixes: 7d06d5895c15 ("Revert "Bluetooth: btusb: fix QCA...suspend/resume"")
Cc: stable@xxxxxxxxxxxxxxx
Cc: Leif Liddy <leif.linux@xxxxxxxxx>
Cc: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
Cc: Brian Norris <briannorris@xxxxxxxxxxxx>
Cc: Daniel Drake <drake@xxxxxxxxxxxx>
Cc: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
Note:
1) Once this has been merged, the 2 commits adding QCA device entries to
drivers/usb/core/quirks.c should be reverted or dropped from bluetooth-next.
2) I don't have any of the affected devices, please test
---
  drivers/bluetooth/btusb.c | 22 ++++++++++------------
  1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index 4764100a5888..c4689f03220f 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -23,6 +23,7 @@
#include <linux/module.h>
  #include <linux/usb.h>
+#include <linux/usb/quirks.h>
  #include <linux/firmware.h>
  #include <linux/of_device.h>
  #include <linux/of_irq.h>
@@ -388,9 +389,8 @@ static const struct usb_device_id blacklist_table[] = {
  #define BTUSB_FIRMWARE_LOADED	7
  #define BTUSB_FIRMWARE_FAILED	8
  #define BTUSB_BOOTING		9
-#define BTUSB_RESET_RESUME	10
-#define BTUSB_DIAG_RUNNING	11
-#define BTUSB_OOB_WAKE_ENABLED	12
+#define BTUSB_DIAG_RUNNING	10
+#define BTUSB_OOB_WAKE_ENABLED	11
struct btusb_data {
  	struct hci_dev       *hdev;
@@ -3118,6 +3118,12 @@ static int btusb_probe(struct usb_interface *intf,
  	if (id->driver_info & BTUSB_QCA_ROME) {
  		data->setup_on_usb = btusb_setup_qca;
  		hdev->set_bdaddr = btusb_set_bdaddr_ath3012;
+
+		/* QCA Rome devices lose their updated firmware over suspend,
+		 * but the USB hub doesn't notice any status change.
+		 * explicitly request a device reset on resume.
+		 */
+		interface_to_usbdev(intf)->quirks |= USB_QUIRK_RESET_RESUME;
  	}
#ifdef CONFIG_BT_HCIBTUSB_RTL
@@ -3128,7 +3134,7 @@ static int btusb_probe(struct usb_interface *intf,
  		 * but the USB hub doesn't notice any status change.
  		 * Explicitly request a device reset on resume.
  		 */
-		set_bit(BTUSB_RESET_RESUME, &data->flags);
+		interface_to_usbdev(intf)->quirks |= USB_QUIRK_RESET_RESUME;
  	}
  #endif
@@ -3297,14 +3303,6 @@ static int btusb_suspend(struct usb_interface *intf, pm_message_t message)
  		enable_irq(data->oob_wake_irq);
  	}
- /* Optionally request a device reset on resume, but only when
-	 * wakeups are disabled. If wakeups are enabled we assume the
-	 * device will stay powered up throughout suspend.
-	 */
-	if (test_bit(BTUSB_RESET_RESUME, &data->flags) &&
-	    !device_may_wakeup(&data->udev->dev))
-		data->udev->reset_resume = 1;
-
  	return 0;
  }
--
2.14.3