linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Rich Felker <dalias@libc.org>
To: Christoph Hellwig <hch@lst.de>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>,
	linux-sh@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 09/10] sh: don't allow non-coherent DMA for NOMMU
Date: Thu, 27 Aug 2020 22:11:53 -0400	[thread overview]
Message-ID: <20200828021152.GU3265@brightrain.aerifal.cx> (raw)
In-Reply-To: <20200828020045.GT3265@brightrain.aerifal.cx>

On Thu, Aug 27, 2020 at 10:00:48PM -0400, Rich Felker wrote:
> On Tue, Jul 14, 2020 at 02:18:55PM +0200, Christoph Hellwig wrote:
> > The code handling non-coherent DMA depends on being able to remap code
> > as non-cached.  But that can't be done without an MMU, so using this
> > option on NOMMU builds is broken.
> > 
> > Signed-off-by: Christoph Hellwig <hch@lst.de>
> > ---
> >  arch/sh/Kconfig | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
> > index f8027eee08edae..337eb496c45a0a 100644
> > --- a/arch/sh/Kconfig
> > +++ b/arch/sh/Kconfig
> > @@ -61,6 +61,7 @@ config SUPERH
> >  	select MAY_HAVE_SPARSE_IRQ
> >  	select MODULES_USE_ELF_RELA
> >  	select NEED_SG_DMA_LENGTH
> > +	select NO_DMA if !MMU && !DMA_COHERENT
> >  	select NO_GENERIC_PCI_IOPORT_MAP if PCI
> >  	select OLD_SIGACTION
> >  	select OLD_SIGSUSPEND
> > @@ -135,7 +136,7 @@ config DMA_COHERENT
> >  	bool
> 
> This change broke SD card support on J2 because MMC_SPI spuriously
> depends on HAS_DMA. It looks like it can be fixed just by removing
> that dependency from drivers/mmc/host/Kconfig.

It can't. mmp_spi_probe fails with ENOMEM, probably due to trying to
do some DMA setup thing that's not going to be needed if the
underlying SPI device doesn't support/use DMA.

Rich

  reply	other threads:[~2020-08-28  2:11 UTC|newest]

Thread overview: 62+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-14 12:18 ioremap and dma cleanups and fixes for superh (2nd resend) Christoph Hellwig
2020-07-14 12:18 ` [PATCH 01/10] sh: remove -Werror from Makefiles Christoph Hellwig
2020-07-14 12:18 ` [PATCH 02/10] sh: sort the selects for SUPERH alphabetically Christoph Hellwig
2020-07-14 12:18 ` [PATCH 03/10] sh: remove __KERNEL__ ifdefs from non-UAPI headers Christoph Hellwig
2020-07-14 12:18 ` [PATCH 04/10] sh: move ioremap_fixed details out of <asm/io.h> Christoph Hellwig
2020-07-14 12:18 ` [PATCH 05/10] sh: move the ioremap implementation out of line Christoph Hellwig
2020-07-14 12:18 ` [PATCH 06/10] sh: don't include <asm/io_trapped.h> in <asm/io.h> Christoph Hellwig
2020-07-14 12:18 ` [PATCH 07/10] sh: unexport register_trapped_io and match_trapped_io_handler Christoph Hellwig
2020-07-14 12:18 ` [PATCH 08/10] dma-mapping: consolidate the NO_DMA definition in kernel/dma/Kconfig Christoph Hellwig
2020-07-21  3:17   ` Rich Felker
2020-07-21  5:11     ` Christoph Hellwig
2020-07-22  0:43       ` Rich Felker
2020-07-14 12:18 ` [PATCH 09/10] sh: don't allow non-coherent DMA for NOMMU Christoph Hellwig
2020-08-28  2:00   ` Rich Felker
2020-08-28  2:11     ` Rich Felker [this message]
2020-08-28  4:24       ` Christoph Hellwig
2020-08-28  9:26         ` Ulf Hansson
2020-08-28 15:09           ` Rich Felker
2020-08-29  8:31             ` Christoph Hellwig
2020-08-31 11:28               ` Ulf Hansson
2020-07-14 12:18 ` [PATCH 10/10] sh: use the generic dma coherent remap allocator Christoph Hellwig
2020-07-14 12:31 ` ioremap and dma cleanups and fixes for superh (2nd resend) John Paul Adrian Glaubitz
2020-07-14 15:59   ` Rich Felker
2020-07-14 16:10     ` John Paul Adrian Glaubitz
2020-07-14 23:12       ` John Paul Adrian Glaubitz
2020-07-14 23:14         ` John Paul Adrian Glaubitz
2020-07-15  3:12         ` Rich Felker
2020-07-15  6:39           ` John Paul Adrian Glaubitz
2020-07-15  7:27         ` Geert Uytterhoeven
2020-07-15  7:37           ` John Paul Adrian Glaubitz
2020-07-15  8:06             ` Geert Uytterhoeven
2020-07-15  7:46           ` John Paul Adrian Glaubitz
2020-07-15  7:51             ` John Paul Adrian Glaubitz
2020-07-15  8:11               ` Geert Uytterhoeven
2020-07-15  8:27                 ` John Paul Adrian Glaubitz
2020-07-15 14:37                   ` John Paul Adrian Glaubitz
2020-07-15 15:39                     ` John Paul Adrian Glaubitz
2020-07-15 16:18                     ` John Paul Adrian Glaubitz
2020-07-15 18:21                       ` Geert Uytterhoeven
2020-07-15 18:27                         ` John Paul Adrian Glaubitz
2020-07-16  9:40                         ` Peter Zijlstra
2020-07-16 10:05                           ` John Paul Adrian Glaubitz
2020-07-16 10:29                           ` peterz
2020-07-16 10:54                             ` John Paul Adrian Glaubitz
2020-07-16 11:01                               ` peterz
2020-07-16 11:03                                 ` John Paul Adrian Glaubitz
2020-07-16 11:37                                   ` peterz
2020-07-16 12:04                                     ` peterz
2020-07-16 18:14                                       ` John Paul Adrian Glaubitz
2020-07-16 19:28                                         ` Peter Zijlstra
2020-07-16 19:33                                           ` John Paul Adrian Glaubitz
2020-07-16 11:30                       ` John Paul Adrian Glaubitz
2020-07-15  8:07             ` Geert Uytterhoeven
2020-07-16 11:31           ` John Paul Adrian Glaubitz
2020-07-20 13:38         ` Christoph Hellwig
2020-07-20 13:42           ` John Paul Adrian Glaubitz
2020-07-20 14:53             ` Rich Felker
2020-07-21  3:20               ` Rich Felker
  -- strict thread matches above, loose matches on Subject: below --
2020-06-26  8:07 ioremap and dma cleanups and fixes for superh (resend) Christoph Hellwig
2020-06-26  8:07 ` [PATCH 09/10] sh: don't allow non-coherent DMA for NOMMU Christoph Hellwig
2020-06-28  1:01   ` Rob Landley
2020-06-28  7:24     ` Christoph Hellwig
2020-03-24 16:26 ioremap and dma cleanups and fixes for superh Christoph Hellwig
2020-03-24 16:26 ` [PATCH 09/10] sh: don't allow non-coherent DMA for NOMMU Christoph Hellwig

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:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

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

  git send-email \
    --in-reply-to=20200828021152.GU3265@brightrain.aerifal.cx \
    --to=dalias@libc.org \
    --cc=hch@lst.de \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-sh@vger.kernel.org \
    --cc=ysato@users.sourceforge.jp \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).