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Wed, 01 Apr 2026 19:45:48 -0700 (PDT) Date: Wed, 1 Apr 2026 22:45:47 -0400 From: Alan Stern To: Tao Xue Cc: gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, caiyadong@huawei.com, stable@kernel.org Subject: Re: [PATCH] usb: core: Fix bandwidth for devices with invalid wBytesPerInterval Message-ID: <31026029-d7df-4e84-977b-2d6f74fcc80b@rowland.harvard.edu> References: <20260402021400.28853-1-xuetao09@huawei.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260402021400.28853-1-xuetao09@huawei.com> On Thu, Apr 02, 2026 at 10:14:00AM +0800, Tao Xue wrote: > As specified in Section 4.14.2 of the xHCI Specification, the xHC > reserves bandwidth for periodic endpoints according to bInterval and > wBytesPerInterval (Max ESIT Payload). > > Some peripherals report an invalid wBytesPerInterval in their device > descriptor, which is either 0 or smaller than the actual data length > transmitted. This issue is observed on ASIX AX88179 series USB 3.0 > Ethernet adapters. Do we log these invalid values when we parse the endpoint and their companion descriptors? We should -- and we can fix up any errors then, just once. Alan Stern