6.6-stable review patch. If anyone has any objections, please let me know.
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From: Selvarasu Ganesan selvarasu.g@samsung.com
commit 45eae113dccaf8e502090ecf5b3d9e9b805add6f upstream.
This commit addresses a rarely observed endpoint command timeout which causes kernel panic due to warn when 'panic_on_warn' is enabled and unnecessary call trace prints when 'panic_on_warn' is disabled. It is seen during fast software-controlled connect/disconnect testcases. The following is one such endpoint command timeout that we observed:
1. Connect ======= ->dwc3_thread_interrupt ->dwc3_ep0_interrupt ->configfs_composite_setup ->composite_setup ->usb_ep_queue ->dwc3_gadget_ep0_queue ->__dwc3_gadget_ep0_queue ->__dwc3_ep0_do_control_data ->dwc3_send_gadget_ep_cmd
2. Disconnect ========== ->dwc3_thread_interrupt ->dwc3_gadget_disconnect_interrupt ->dwc3_ep0_reset_state ->dwc3_ep0_end_control_data ->dwc3_send_gadget_ep_cmd
In the issue scenario, in Exynos platforms, we observed that control transfers for the previous connect have not yet been completed and end transfer command sent as a part of the disconnect sequence and processing of USB_ENDPOINT_HALT feature request from the host timeout. This maybe an expected scenario since the controller is processing EP commands sent as a part of the previous connect. It maybe better to remove WARN_ON in all places where device endpoint commands are sent to avoid unnecessary kernel panic due to warn.
Cc: stable stable@kernel.org Co-developed-by: Akash M akash.m5@samsung.com Signed-off-by: Akash M akash.m5@samsung.com Signed-off-by: Selvarasu Ganesan selvarasu.g@samsung.com Acked-by: Thinh Nguyen Thinh.Nguyen@synopsys.com Reviewed-by: Sebastian Andrzej Siewior bigeasy@linutronix.de Link: https://lore.kernel.org/r/20250808125315.1607-1-selvarasu.g@samsung.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/dwc3/ep0.c | 20 ++++++++++++++++---- drivers/usb/dwc3/gadget.c | 10 ++++++++-- 2 files changed, 24 insertions(+), 6 deletions(-)
--- a/drivers/usb/dwc3/ep0.c +++ b/drivers/usb/dwc3/ep0.c @@ -288,7 +288,9 @@ void dwc3_ep0_out_start(struct dwc3 *dwc dwc3_ep0_prepare_one_trb(dep, dwc->ep0_trb_addr, 8, DWC3_TRBCTL_CONTROL_SETUP, false); ret = dwc3_ep0_start_trans(dep); - WARN_ON(ret < 0); + if (ret < 0) + dev_err(dwc->dev, "ep0 out start transfer failed: %d\n", ret); + for (i = 2; i < DWC3_ENDPOINTS_NUM; i++) { struct dwc3_ep *dwc3_ep;
@@ -1061,7 +1063,9 @@ static void __dwc3_ep0_do_control_data(s ret = dwc3_ep0_start_trans(dep); }
- WARN_ON(ret < 0); + if (ret < 0) + dev_err(dwc->dev, + "ep0 data phase start transfer failed: %d\n", ret); }
static int dwc3_ep0_start_control_status(struct dwc3_ep *dep) @@ -1078,7 +1082,12 @@ static int dwc3_ep0_start_control_status
static void __dwc3_ep0_do_control_status(struct dwc3 *dwc, struct dwc3_ep *dep) { - WARN_ON(dwc3_ep0_start_control_status(dep)); + int ret; + + ret = dwc3_ep0_start_control_status(dep); + if (ret) + dev_err(dwc->dev, + "ep0 status phase start transfer failed: %d\n", ret); }
static void dwc3_ep0_do_control_status(struct dwc3 *dwc, @@ -1121,7 +1130,10 @@ void dwc3_ep0_end_control_data(struct dw cmd |= DWC3_DEPCMD_PARAM(dep->resource_index); memset(¶ms, 0, sizeof(params)); ret = dwc3_send_gadget_ep_cmd(dep, cmd, ¶ms); - WARN_ON_ONCE(ret); + if (ret) + dev_err_ratelimited(dwc->dev, + "ep0 data phase end transfer failed: %d\n", ret); + dep->resource_index = 0; }
--- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -1765,7 +1765,11 @@ static int __dwc3_stop_active_transfer(s dep->flags |= DWC3_EP_DELAY_STOP; return 0; } - WARN_ON_ONCE(ret); + + if (ret) + dev_err_ratelimited(dep->dwc->dev, + "end transfer failed: %d\n", ret); + dep->resource_index = 0;
if (!interrupt) @@ -4045,7 +4049,9 @@ static void dwc3_clear_stall_all_ep(stru dep->flags &= ~DWC3_EP_STALL;
ret = dwc3_send_clear_stall_ep_cmd(dep); - WARN_ON_ONCE(ret); + if (ret) + dev_err_ratelimited(dwc->dev, + "failed to clear STALL on %s\n", dep->name); } }