From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794769672; b=tTPsFN/s3XB5yskYETTZGw2ENRC2TCqnZT/MlgPdi8yA0eSENKg0SGHh7W8yWiw+4KSb JVVFOZKrYWQ8adhLZ45QF0BDibQE3y0IBdkmuOhRgm4ddGSRdmbHWqn1hYfeTAoUpIOhC EE8tF6hPkC+rK1ESEfxpoySJIUrL68Y5l2N0+26h4ZRpuIciTgPBjWNaA61SZ8exw/Oif sIcdn6pNXxcGpCfEpFUJOpNuPHXxXAbVO1CZv3KhSQFO/GmFMmC+Fe66ChxVpjcm+16DI 7RN80MqJ4co872SLVVqk0NLsIQwO/QuEpCwY2aw8l0COOD/W7uPxgomCOsx09l1uXhQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794769672; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=zL5ieg6aaOkL+NBqveWK6L3RbexrHTL3RdMkqHY7yPs=; b=dUVLSG/U89kTwUmf5CZeqzooZ2awjirdLr47GTQtyCG//ckVmwZ5YGtPz1yIQaeQR+2U HKB6zQkrxIqnNOa6u2KE6EAqcJ0RKCHSRwuIpjJsEeLet2TD8kG+6laOd9E5HzAB8NUUG DE1uHp9HqJgYcR8kagMdVP9Os6k+K2eThIZJkEPy2Tf7BEOtpgr4FHgnkLGynxUqn/RN8 tSErNO1ipkRddUxct7FkYN06fY06QExYvCHqpYZUmxOE0FPnMoLtByXDR8T9BOYVTApp6 hzbSWoUm61vS/RhwAIzHoFm/ijE94SoK8OBZNifcXqI2ibR5mlKa+i3jLpoYofsinIg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=RwmXQcmo; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A8EC8606A31A for ; Sun, 15 Nov 2026 19:07:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=RwmXQcmo Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1D5641F000C4; Sun, 15 Nov 2026 19:07:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794769672; bh=zL5ieg6aaOkL+NBqveWK6L3RbexrHTL3RdMkqHY7yPs=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=RwmXQcmosLYtlvSbuPXgPpe81dZhaSteR7DwuNpLh7tfvoTvIKNeaccMrvuT6zZSM 64InVDcQZ1wV650Mgr7GRWeC1qfIN6xtU4mct6/xFNj0MjprSXwPo1HCC+pbsFaqZC WAalpmyYPkfAUkkrx4XV2SP7waItbpNnrvy0m2NJ5WW/HgKIyUdDfw/bpvmScUujtm yifQyrJRkO86VynhDtO5xc8zc4UAHV8kvl+0YrDNULv7SrxOur5D7i/Eac/VZjPV8/ 5kjrgHJEEsTEtSCV6FhvIDT4EjVKZl/YHLwq7j1GvuBZIi8nUOvctKhoplQp5hgp+6 DuOnJ4qHtB8PQ== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH 3/3] usb: dwc2: gadget: make descriptors visible before the endpoint is enabled Reply-To: sashiko-reviews@lists.linux.dev To: "Vadim Yuzifovich" Cc: linux-usb@vger.kernel.org In-Reply-To: <20261115185335.782678-4-vadim@yuzi.co> References: <20261115185335.782678-1-vadim@yuzi.co> <20261115185335.782678-4-vadim@yuzi.co> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Sun, 15 Nov 2026 19:07:49 +0000 X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list Thank you for your contribution! Sashiko AI review found 1 potential issue to consider: - [Medium] usb: dwc2: gadget: dwc2_gadget_desc_visible() skipped when isoc ring is full -- commit ff96d0bc699669e80418e1239ed82d2f723a61f0 Author: Vadim Yuzifovich usb: dwc2: gadget: make descriptors visible before the endpoint is enabled This commit adds dwc2_gadget_desc_visible() to read back the last written DMA descriptor between two full memory barriers before enabling an endpoint in descriptor DMA mode. > diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c > index 046b5b04503bd..fe37250fec6c7 100644 > --- a/drivers/usb/dwc2/gadget.c > +++ b/drivers/usb/dwc2/gadget.c [ ... ] > @@ -1021,6 +1044,9 @@ static void dwc2_gadget_start_isoc_ddma(struct dwc2= _hsotg_ep *hs_ep) > depctl =3D hs_ep->dir_in ? DIEPCTL(index) : DOEPCTL(index); > dma_reg =3D hs_ep->dir_in ? DIEPDMA(index) : DOEPDMA(index); > =20 > + if (hs_ep->next_desc) > + dwc2_gadget_desc_visible(&hs_ep->desc_list[hs_ep->next_desc - 1]); [Severity: Medium] Does this skip dwc2_gadget_desc_visible() when the isochronous descriptor ring is full? dwc2_gadget_start_isoc_ddma() returns early when hs_ep->queue is empty, so at least one descriptor is always filled. When MAX_DMA_DESC_NUM_HS_ISOC or more requests are queued, dwc2_gadget_fill_isoc_desc() fills all 256 descriptors and wraps hs_ep->next_desc back to 0: drivers/usb/dwc2/gadget.c:dwc2_gadget_fill_isoc_desc() { ... /* Update index of last configured entry in the chain */ hs_ep->next_desc++; if (hs_ep->next_desc >=3D MAX_DMA_DESC_NUM_HS_ISOC) hs_ep->next_desc =3D 0; return 0; } When hs_ep->next_desc wraps to 0, the if (hs_ep->next_desc) check skips dwc2_gadget_desc_visible() instead of reading back hs_ep->desc_list[MAX_DMA_DESC_NUM_HS_ISOC - 1], leaving the descriptor writes in flight when the endpoint is enabled and allowing the BNA error to occur. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261115185335.7826= 78-1-vadim@yuzi.co?part=3D3