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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 21D56C2BB3F for ; Wed, 15 Nov 2023 19:27:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=cRsAWfTXb6+m4XjzgAfQfT/PhGrhOjhTPTHBocB994w=; b=pgWdiWmiw+34+s 4K1XAD4CxwZiQqe1f0cIELY1S1PzK/VBeqLxB/bJYKOaTNU9livPriNeTGPMcKMb21THQ0kRHnP5e 5pr4VEj3h9AlOiyzYKH0NPEOc+wcUj8AWhxt7c8+VJdORxwKiTQlnIdglo/62X0DKrBQEr/XxRz6A KU0i9/0x+irOPtHP0zsRSv0C9HUbFkOapiKdwEksXTOqXHipWcDbUPfxTwqPlAIOXLRjJDw4844Bx K4LLedXhQozQt2y/aKuG9W0HWqQ30C6D0ciEEE3CbtVdlLtnaCN17++/Zi5vRhOrL+ubrEqdCU+gw KdR3T7sZC+EDc3BPj5IA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1r3LXZ-001aMa-17; Wed, 15 Nov 2023 19:27:09 +0000 Received: from perceval.ideasonboard.com ([213.167.242.64]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1r3LXV-001aM6-14; Wed, 15 Nov 2023 19:27:07 +0000 Received: from pendragon.ideasonboard.com (213-243-189-158.bb.dnainternet.fi [213.243.189.158]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 1B11F29A; Wed, 15 Nov 2023 20:26:33 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1700076393; bh=HuvqlF4fz7sV1Btrlh+F7H9LaWiQ+2kuf+3ugMlgbII=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=SH3pZ8UsCtCH4aQvZPeCAc/JEA/VsNBXYIruQ7dpIXgRP2IGApeRfodtdKOUtGSpQ 0tOr+1ARI49S/OtijiXwNSvJPJsz59o9H2NBHHE56PSaGaE0p4IY14TOJCG81AV3Yt ovyzzYOmN4QpKG4xN/kKoiu6Rj5D6hoe0jcEpkEg= Date: Wed, 15 Nov 2023 21:27:05 +0200 From: Laurent Pinchart To: Stefan Wahren Cc: Umang Jain , linux-media@vger.kernel.org, kernel-list@raspberrypi.com, linux-kernel@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-staging@lists.linux.dev, Dave Stevenson , Kieran Bingham , "Ricardo B . Marliere" , Dan Carpenter Subject: Re: [PATCH v2 05/15] staging: mmal-vchiq: Use vc-sm-cma to support zero copy Message-ID: <20231115192705.GC21100@pendragon.ideasonboard.com> References: <20231109210309.638594-1-umang.jain@ideasonboard.com> <20231109210309.638594-6-umang.jain@ideasonboard.com> <3b9ec650-8a99-4bac-9ac9-d2cd87efced5@i2se.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <3b9ec650-8a99-4bac-9ac9-d2cd87efced5@i2se.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231115_112705_527192_45CE900D X-CRM114-Status: GOOD ( 24.66 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Nov 15, 2023 at 08:03:47PM +0100, Stefan Wahren wrote: > Hi Umang, > > Am 09.11.23 um 22:02 schrieb Umang Jain: > > From: Dave Stevenson > > > > With the vc-sm-cma driver we can support zero copy of buffers between > > the kernel and VPU. Add this support to mmal-vchiq. > > > > Signed-off-by: Dave Stevenson > > Signed-off-by: Umang Jain > > --- > > .../staging/vc04_services/vchiq-mmal/Kconfig | 1 + > > .../vc04_services/vchiq-mmal/mmal-common.h | 4 + > > .../vc04_services/vchiq-mmal/mmal-vchiq.c | 84 +++++++++++++++++-- > > .../vc04_services/vchiq-mmal/mmal-vchiq.h | 1 + > > 4 files changed, 83 insertions(+), 7 deletions(-) > > > > diff --git a/drivers/staging/vc04_services/vchiq-mmal/Kconfig b/drivers/staging/vc04_services/vchiq-mmal/Kconfig > > index c99525a0bb45..a7c1a7bf516e 100644 > > --- a/drivers/staging/vc04_services/vchiq-mmal/Kconfig > > +++ b/drivers/staging/vc04_services/vchiq-mmal/Kconfig > > @@ -1,6 +1,7 @@ > > config BCM2835_VCHIQ_MMAL > > tristate "BCM2835 MMAL VCHIQ service" > > depends on BCM2835_VCHIQ > > + select BCM_VC_SM_CMA > > i think we need more explanation in the commit message of the relation > between these both modules. > > On the one side BCM_VC_SM_CMA should be a driver, but it's not a driver > for a specific hardware. It looks like more an extension of VCHIQ MMAL > or does other (maybe not yet imported) vc04 driver make also use of this. > > My question is: is BCM_VC_SM_CMA a real member on the VCHIQ bus and why? The vchiq_device pointer passed to the vc_sm_cma probe function is used in the driver for the sole purpose of accessing the underlying struct device, which, beside being used for dev_*() log calls, is just passed to dma_buf_attach(). It does indeed appear to be more of a service than a device. -- Regards, Laurent Pinchart _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel