Re: next take at setting up a dma mask by default for platform devices v2
On Fri, Aug 16, 2019 at 08:24:29AM +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 have already been queued up by Greg > and are only included for completeness. Note to everyone. The first two patches in this series is already in 5.3-rc5. I've applied the rest of the series to my usb-next branch (with the 6th patch landing there later today.) They are scheduled to be merge to Linus in 5.4-rc1. Christoph, thanks so much for these cleanups. greg k-h
next take at setting up a dma mask by default for platform devices v2
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 have already been queued up by Greg and are only included for completeness. Changes since v1: - fix a compile error in the ppc of ohci driver - revamp the last patch to get rid of the archdata callout entirely.
Re: next take at setting up a dma mask by default for platform devices
On Thu, 15 Aug 2019, Christoph Hellwig wrote: > On Thu, Aug 15, 2019 at 03:23:18PM +0200, Greg Kroah-Hartman wrote: > > 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. > > I have a respun version ready, but I'd really like to hear some > comments from usb developers about the approach before spamming > everyone again.. I didn't see any problems with your approach at first glance; it looked like a good idea. Alan Stern
Re: next take at setting up a dma mask by default for platform devices
On Thu, Aug 15, 2019 at 03:25:31PM +0200, Christoph Hellwig wrote: > On Thu, Aug 15, 2019 at 03:23:18PM +0200, Greg Kroah-Hartman wrote: > > 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. > > I have a respun version ready, but I'd really like to hear some > comments from usb developers about the approach before spamming > everyone again.. Spam away, we can take it :)
Re: next take at setting up a dma mask by default for platform devices
On Thu, Aug 15, 2019 at 03:23:18PM +0200, Greg Kroah-Hartman wrote: > 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. I have a respun version ready, but I'd really like to hear some comments from usb developers about the approach before spamming everyone again..
Re: next take at setting up a dma mask by default for platform devices
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
next take at setting up a dma mask by default for platform devices
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.
