Linux-USB Archive on
 help / color / Atom feed
From: Christoph Hellwig <>
To: Greg Kroah-Hartman <>,
	Maxime Chevallier <>
Cc: Gavin Li <>,
	Laurentiu Tudor <>,
	Minas Harutyunyan <>,
	Alan Stern <>,
	Geoff Levand <>,
	Michal Simek <>,
	Shawn Guo <>,
	Sascha Hauer <>,
	Pengutronix Kernel Team <>,
	Fabio Estevam <>,
	NXP Linux Team <>,
	Mathias Nyman <>, Bin Liu <>,,,,,,,
Subject: next take at setting up a dma mask by default for platform devices v2
Date: Fri, 16 Aug 2019 08:24:29 +0200
Message-ID: <> (raw)

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.

             reply index

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-16  6:24 Christoph Hellwig [this message]
2019-08-16  6:24 ` [PATCH 1/6] usb: don't create dma pools for HCDs with a localmem_pool Christoph Hellwig
2019-08-16  6:24 ` [PATCH 2/6] usb: add a hcd_uses_dma helper Christoph Hellwig
2019-08-16  6:24 ` [PATCH 3/6] usb: add a HCD_DMA flag instead of guestimating DMA capabilities Christoph Hellwig
2019-08-16  6:24 ` [PATCH 4/6] usb/max3421: remove the dummy {un,}map_urb_for_dma methods Christoph Hellwig
2019-08-16  6:24 ` [PATCH 5/6] dma-mapping: remove is_device_dma_capable Christoph Hellwig
2019-08-16  6:24 ` [PATCH 6/6] driver core: initialize a default DMA mask for platform device Christoph Hellwig
2019-08-16  7:39   ` Geert Uytterhoeven
2019-08-22 17:11 ` next take at setting up a dma mask by default for platform devices v2 Greg Kroah-Hartman

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-USB Archive on

Archives are clonable:
	git clone --mirror linux-usb/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-usb linux-usb/ \
	public-inbox-index linux-usb

Example config snippet for mirrors

Newsgroup available over NNTP:

AGPL code for this site: git clone