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* [PATCH v2] Bluetooth: btusb: Allow firmware re-download when version matches
@ 2026-04-29 12:12 Shuai Zhang
  2026-04-29 14:56 ` [v2] " bluez.test.bot
  2026-04-29 15:17 ` [PATCH v2] " Luiz Augusto von Dentz
  0 siblings, 2 replies; 7+ messages in thread
From: Shuai Zhang @ 2026-04-29 12:12 UTC (permalink / raw)
  To: Marcel Holtmann, Luiz Augusto von Dentz
  Cc: linux-bluetooth, linux-kernel, linux-arm-msm, cheng.jiang,
	quic_chezhou, wei.deng, jinwang.li, mengshi.wu, shuai.zhang

The Bluetooth host decides whether to download firmware by reading the
controller firmware download completion flag and firmware version
information.

If a USB error occurs during the firmware download process (for example
due to a USB disconnect), the download is aborted immediately. An
incomplete firmware transfer does not cause the controller to set the
download completion flag, but the firmware version information may be
updated at an early stage of the download process.

In this case, after USB reconnection, the host attempts to re-download
the firmware because the download completion flag is not set. However,
since the controller reports the same firmware version as the target
firmware, the download is skipped. This ultimately results in the
firmware not being properly updated on the controller.

This change removes the restriction that skips firmware download when
the versions are equal. It covers scenarios where the USB connection
can be disconnected at any time and ensures that firmware download can
be retriggered after USB reconnection, allowing the Bluetooth firmware
to be correctly and completely updated.

Signed-off-by: Shuai Zhang <shuai.zhang@oss.qualcomm.com>
---
Changes v2:
- Update code comments and commit message to reflect the correct logic.
- Align the commit title with upstream conventions.
- Link v1
  https://lore.kernel.org/all/20260108074353.1027877-1-shuai.zhang@oss.qualcomm.com/
---
 drivers/bluetooth/btusb.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index 572091e60..70abbabea 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -3550,7 +3550,13 @@ static int btusb_setup_qca_load_rampatch(struct hci_dev *hdev,
 		    "firmware rome 0x%x build 0x%x",
 		    rver_rom, rver_patch, ver_rom, ver_patch);
 
-	if (rver_rom != ver_rom || rver_patch <= ver_patch) {
+	/* Allow rampatch when the patch version equals the firmware version.
+	 * A firmware download may be aborted by a transient USB error (e.g.
+	 * disconnect) after the controller updates version info but before
+	 * completion.
+	 * Allowing equal versions enables re-flashing during recovery.
+	 */
+	if (rver_rom != ver_rom || rver_patch < ver_patch) {
 		bt_dev_err(hdev, "rampatch file version did not match with firmware");
 		err = -EINVAL;
 		goto done;
-- 
2.34.1


^ permalink raw reply related	[flat|nested] 7+ messages in thread
* Re: [PATCH v2] Bluetooth: btusb: Allow firmware re-download when version matches
@ 2026-05-14  2:44 makro-kernel
  0 siblings, 0 replies; 7+ messages in thread
From: makro-kernel @ 2026-05-14  2:44 UTC (permalink / raw)
  To: shuai.zhang@oss.qualcomm.com
  Cc: luiz.dentz@gmail.com, marcel@holtmann.org,
	linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-arm-msm@vger.kernel.org

Hi Shuai, Luiz,

I sent a patch earlier today touching the same function for a related
but distinct failure mode in the same family of chips, and only just
saw this thread.

  https://lore.kernel.org/linux-bluetooth/aD_Lix2EVXOHmbZ4L1CunlWiLqfiKlU_1_FcVh4CBuIgud4kmE_544xjW2zFKsmh4pNAo9yIQ7q8_GZ4YcmgAXPp8LgW9rfWKqnu06WSjgk=@proton.me/T/#u

In my case the *outer* check fails first: on Foxconn USB 0489:e10a
(Qualcomm WCN6855/WCN785x, ROM 0x00190200) the chip reports
QCA_CHECK_STATUS = 0xe0 (PATCH_UPDATED | SYSCFG_UPDATED) on every
probe, so btusb_setup_qca() never reaches load_rampatch() or
load_nvm(), returns 0, and the controller runs unpatched firmware.

AVDTP setup later fails on Acquire and A2DP audio cannot stream. The
PATCH_UPDATED bit appears to persist across cold boots somewhere on
chip -- originally set by Windows on dual-boot-then-Linux systems
we've seen, but the bit sticks even after a successful Linux firmware
upload, so subsequent boots also see 0xe0 and skip.

The rampatch itself also persists on this silicon at least across
suspend/hibernate resume cycles and driver reload (whether it
survives a true cold boot I haven't isolated). Either way, once an
upload has succeeded the chip reports patch_version equal to the
file's version on subsequent probes, which is exactly the condition
your patch addresses. With my outer bypass in place but without your
inner change, the second and subsequent probes hit the existing
`rver_patch <= ver_patch` check, return -EINVAL, and controller
setup aborts entirely:

  Bluetooth: hci0: using rampatch file: qca/rampatch_usb_00190200.bin
  Bluetooth: hci0: QCA: patch rome 0x190200 build 0x8567, firmware rome 0x190200 build 0x8567
  Bluetooth: hci0: rampatch file version did not match with firmware
  (btusb_setup_qca returns -EINVAL, hci0 never finishes registering)

So your fix is doing the right thing here, and on this hardware both
sides are needed together for the chip to come up cleanly across
reload / reboot cycles.

In my local tree I skip reuploading on equal versions rather than 
re-uploading on every probe:

  if (rver_rom != ver_rom) {
          bt_dev_err(hdev, "rampatch file ROM did not match controller");
          err = -EINVAL;
          goto done;
  }

  if (rver_patch <= ver_patch) {
          bt_dev_info(hdev, "QCA: rampatch already current, skipping download");
          err = 0;
          goto done;
  }

  err = btusb_setup_qca_download_fw(hdev, fw, info->rampatch_hdr);

Best,
Makro

^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2026-05-14  2:45 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-04-29 12:12 [PATCH v2] Bluetooth: btusb: Allow firmware re-download when version matches Shuai Zhang
2026-04-29 14:56 ` [v2] " bluez.test.bot
2026-04-29 15:17 ` [PATCH v2] " Luiz Augusto von Dentz
2026-04-29 16:14   ` Luiz Augusto von Dentz
2026-05-13  7:52     ` Shuai Zhang
2026-05-13  7:50   ` Shuai Zhang
  -- strict thread matches above, loose matches on Subject: below --
2026-05-14  2:44 makro-kernel

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