From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B3944CA5501 for ; Wed, 13 Sep 2023 07:16:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238477AbjIMHQr (ORCPT ); Wed, 13 Sep 2023 03:16:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36878 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238551AbjIMHQo (ORCPT ); Wed, 13 Sep 2023 03:16:44 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BB4BC1982; Wed, 13 Sep 2023 00:16:40 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9B651C433C8; Wed, 13 Sep 2023 07:16:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1694589400; bh=jbMSHPEy4vx/r2wm/ygIl/jEIoje24uhM4eGXw0OuRo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=oXnH0fp5+9oely5ZhPDGV40JD4mjLCFM54IsFTQ/bghhl7pxnimSDXtcNxLgDCZ6m eRp0QKq3M1goQKez2s+zLM1eKjql9o0Hlz3whDAvdFKNRCoOdeYVoT9kKY8kMvtfc1 gx9yxeaT9BXqobZAEpbjKe5zoLmUr0oGDWuAvygM= Date: Wed, 13 Sep 2023 09:16:36 +0200 From: Greg KH To: Prashanth K Cc: Mathias Nyman , linux-usb@vger.kernel.org, Hongyu Xie , stable@kernel.org, Hongyu Xie , "# 5 . 15" Subject: Re: [PATCH 1/4] xhci: Keep interrupt disabled in initialization until host is running. Message-ID: <2023091323-splinter-skinless-7c57@gregkh> References: <20220623111945.1557702-1-mathias.nyman@linux.intel.com> <20220623111945.1557702-2-mathias.nyman@linux.intel.com> <42bcb910-7748-cf73-a40d-217c39a63dd1@quicinc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <42bcb910-7748-cf73-a40d-217c39a63dd1@quicinc.com> Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Wed, Sep 13, 2023 at 11:30:41AM +0530, Prashanth K wrote: > > > On 23-06-22 04:49 pm, Mathias Nyman wrote: > > From: Hongyu Xie > > > > irq is disabled in xhci_quiesce(called by xhci_halt, with bit:2 cleared > > in USBCMD register), but xhci_run(called by usb_add_hcd) re-enable it. > > It's possible that you will receive thousands of interrupt requests > > after initialization for 2.0 roothub. And you will get a lot of > > warning like, "xHCI dying, ignoring interrupt. Shouldn't IRQs be > > disabled?". This amount of interrupt requests will cause the entire > > system to freeze. > > This problem was first found on a device with ASM2142 host controller > > on it. > > > > [tidy up old code while moving it, reword header -Mathias] > > Cc: stable@kernel.org > > Signed-off-by: Hongyu Xie > > Signed-off-by: Mathias Nyman > > --- > > drivers/usb/host/xhci.c | 35 ++++++++++++++++++++++------------- > > 1 file changed, 22 insertions(+), 13 deletions(-) > > > > diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c > > index 9ac56e9ffc64..cb99bed5f755 100644 > > --- a/drivers/usb/host/xhci.c > > +++ b/drivers/usb/host/xhci.c > > @@ -611,15 +611,37 @@ static int xhci_init(struct usb_hcd *hcd) > > static int xhci_run_finished(struct xhci_hcd *xhci) > > { > > + unsigned long flags; > > + u32 temp; > > + > > + /* > > + * Enable interrupts before starting the host (xhci 4.2 and 5.5.2). > > + * Protect the short window before host is running with a lock > > + */ > > + spin_lock_irqsave(&xhci->lock, flags); > > + > > + xhci_dbg_trace(xhci, trace_xhci_dbg_init, "Enable interrupts"); > > + temp = readl(&xhci->op_regs->command); > > + temp |= (CMD_EIE); > > + writel(temp, &xhci->op_regs->command); > > + > > + xhci_dbg_trace(xhci, trace_xhci_dbg_init, "Enable primary interrupter"); > > + temp = readl(&xhci->ir_set->irq_pending); > > + writel(ER_IRQ_ENABLE(temp), &xhci->ir_set->irq_pending); > > + > > if (xhci_start(xhci)) { > > xhci_halt(xhci); > > + spin_unlock_irqrestore(&xhci->lock, flags); > > return -ENODEV; > > } > > + > > xhci->cmd_ring_state = CMD_RING_STATE_RUNNING; > > if (xhci->quirks & XHCI_NEC_HOST) > > xhci_ring_cmd_db(xhci); > > + spin_unlock_irqrestore(&xhci->lock, flags); > > + > > return 0; > > } > > @@ -668,19 +690,6 @@ int xhci_run(struct usb_hcd *hcd) > > temp |= (xhci->imod_interval / 250) & ER_IRQ_INTERVAL_MASK; > > writel(temp, &xhci->ir_set->irq_control); > > - /* Set the HCD state before we enable the irqs */ > > - temp = readl(&xhci->op_regs->command); > > - temp |= (CMD_EIE); > > - xhci_dbg_trace(xhci, trace_xhci_dbg_init, > > - "// Enable interrupts, cmd = 0x%x.", temp); > > - writel(temp, &xhci->op_regs->command); > > - > > - temp = readl(&xhci->ir_set->irq_pending); > > - xhci_dbg_trace(xhci, trace_xhci_dbg_init, > > - "// Enabling event ring interrupter %p by writing 0x%x to irq_pending", > > - xhci->ir_set, (unsigned int) ER_IRQ_ENABLE(temp)); > > - writel(ER_IRQ_ENABLE(temp), &xhci->ir_set->irq_pending); > > - > > if (xhci->quirks & XHCI_NEC_HOST) { > > struct xhci_command *command; > This is not available to older kernels [< 5.19]. Can we get this backported > to 5.15 as well? Please let me know if there is some other way to do it. > > Cc: # 5.15 This is not the correct way to submit patches for inclusion in the stable kernel tree. Please read: https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html for how to do this properly.