Re: [PATCH 4.4 095/108] Bluetooth: btusb: Restore QCA Rome suspend/resume fix with a "rewritten" version

[Brian Norris]

On Thu, Feb 15, 2018 at 04:17:32PM +0100, Greg Kroah-Hartman wrote:
> 4.4-stable review patch.  If anyone has any objections, please let me know.

Consider this an objection:

I'm currently arguing that this is unnecessarily regressing power
consumption here:

https://patchwork.kernel.org/patch/10149195/

I'll leave it up to you what to do with this, but if this ends up in
Chromium OS kernels, I'm likely to revert it there...

Brian

> ------------------
> 
> From: Hans de Goede <hdegoede@xxxxxxxxxx>
> 
> commit 61f5acea8737d9b717fcc22bb6679924f3c82b98 upstream.
> 
> 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.
> 
> 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: 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>
> Signed-off-by: Marcel Holtmann <marcel@xxxxxxxxxxxx>
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> 
> ---
>  drivers/bluetooth/btusb.c |   21 ++++++++++-----------
>  1 file changed, 10 insertions(+), 11 deletions(-)
> 
> --- 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 <asm/unaligned.h>
>  
> @@ -360,8 +361,8 @@ static const struct usb_device_id blackl
>  #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_DIAG_RUNNING	10
> +#define BTUSB_OOB_WAKE_ENABLED	11
>  
>  struct btusb_data {
>  	struct hci_dev       *hdev;
> @@ -2969,6 +2970,12 @@ static int btusb_probe(struct usb_interf
>  	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
> @@ -2979,7 +2986,7 @@ static int btusb_probe(struct usb_interf
>  		 * 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
>  
> @@ -3136,14 +3143,6 @@ static int btusb_suspend(struct usb_inte
>  	btusb_stop_traffic(data);
>  	usb_kill_anchored_urbs(&data->tx_anchor);
>  
> -	/* 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;
>  }
>  
> 
>