From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg Kroah-Hartman Subject: Re: next take at setting up a dma mask by default for platform devices Date: Thu, 15 Aug 2019 15:23:18 +0200 Message-ID: <20190815132318.GA27208@kroah.com> References: <20190811080520.21712-1-hch@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20190811080520.21712-1-hch@lst.de> Sender: linux-kernel-owner@vger.kernel.org To: Christoph Hellwig Cc: Maxime Chevallier , Gavin Li , Laurentiu Tudor , Minas Harutyunyan , Alan Stern , Geoff Levand , Michal Simek , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , NXP Linux Team , Olav Kongas , Tony Prisk , Mathias Nyman , Bin Liu , linux-arm-kernel@lists.infradead.org, linux-usb@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, iommu@lists.linux-foundation.org, linux-arch@vger.kerne List-Id: linux-arch.vger.kernel.org On Sun, Aug 11, 2019 at 10:05:14AM +0200, Christoph Hellwig wrote: > Hi all, > > this is another attempt to make sure the dma_mask pointer is always > initialized for platform devices. Not doing so lead to lots of > boilerplate code, and makes platform devices different from all our > major busses like PCI where we always set up a dma_mask. In the long > run this should also help to eventually make dma_mask a scalar value > instead of a pointer and remove even more cruft. > > The bigger blocker for this last time was the fact that the usb > subsystem uses the presence or lack of a dma_mask to check if the core > should do dma mapping for the driver, which is highly unusual. So we > fix this first. Note that this has some overlap with the pending > desire to use the proper dma_mmap_coherent helper for mapping usb > buffers. The first two patches from this series should probably > go into 5.3 and then uses as the basis for the decision to use > dma_mmap_coherent. I've taken the first 2 patches for 5.3-final. Given that patch 3 needs to be fixed, I'll wait for a respin of these before considering them. thanks, greg k-h From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:56330 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731660AbfHONXV (ORCPT ); Thu, 15 Aug 2019 09:23:21 -0400 Date: Thu, 15 Aug 2019 15:23:18 +0200 From: Greg Kroah-Hartman Subject: Re: next take at setting up a dma mask by default for platform devices Message-ID: <20190815132318.GA27208@kroah.com> References: <20190811080520.21712-1-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190811080520.21712-1-hch@lst.de> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Christoph Hellwig Cc: Maxime Chevallier , Gavin Li , Laurentiu Tudor , Minas Harutyunyan , Alan Stern , Geoff Levand , Michal Simek , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , NXP Linux Team , Olav Kongas , Tony Prisk , Mathias Nyman , Bin Liu , linux-arm-kernel@lists.infradead.org, linux-usb@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, iommu@lists.linux-foundation.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Message-ID: <20190815132318.W6fkvdhvxpRgh1TRuf0XcSX3uNCtwL0E51ZKVgXpLs8@z> On Sun, Aug 11, 2019 at 10:05:14AM +0200, Christoph Hellwig wrote: > Hi all, > > this is another attempt to make sure the dma_mask pointer is always > initialized for platform devices. Not doing so lead to lots of > boilerplate code, and makes platform devices different from all our > major busses like PCI where we always set up a dma_mask. In the long > run this should also help to eventually make dma_mask a scalar value > instead of a pointer and remove even more cruft. > > The bigger blocker for this last time was the fact that the usb > subsystem uses the presence or lack of a dma_mask to check if the core > should do dma mapping for the driver, which is highly unusual. So we > fix this first. Note that this has some overlap with the pending > desire to use the proper dma_mmap_coherent helper for mapping usb > buffers. The first two patches from this series should probably > go into 5.3 and then uses as the basis for the decision to use > dma_mmap_coherent. I've taken the first 2 patches for 5.3-final. Given that patch 3 needs to be fixed, I'll wait for a respin of these before considering them. thanks, greg k-h