From: Russell King <rmk+kernel@armlinux.org.uk>
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 4/8] ARM: riscpc: fix DMA
Date: Mon, 20 May 2019 15:47:09 +0100 [thread overview]
Message-ID: <E1hSjZF-0000Y2-CA@rmk-PC.armlinux.org.uk> (raw)
In-Reply-To: <20190520144615.gzrztyhoncyfc5xr@shell.armlinux.org.uk>
DMA got broken a while back in two different ways:
1) a change in the behaviour of disable_irq() to wait for the interrupt
to finish executing causes us to deadlock at the end of DMA.
2) a change to avoid modifying the scatterlist left the first transfer
uninitialised.
DMA is only used with expansion cards, so has gone unnoticed.
Fixes: fa4e99899932 ("[ARM] dma: RiscPC: don't modify DMA SG entries")
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
arch/arm/mach-rpc/dma.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/arch/arm/mach-rpc/dma.c b/arch/arm/mach-rpc/dma.c
index fb48f3141fb4..c4c96661eb89 100644
--- a/arch/arm/mach-rpc/dma.c
+++ b/arch/arm/mach-rpc/dma.c
@@ -131,7 +131,7 @@ static irqreturn_t iomd_dma_handle(int irq, void *dev_id)
} while (1);
idma->state = ~DMA_ST_AB;
- disable_irq(irq);
+ disable_irq_nosync(irq);
return IRQ_HANDLED;
}
@@ -174,6 +174,9 @@ static void iomd_enable_dma(unsigned int chan, dma_t *dma)
DMA_FROM_DEVICE : DMA_TO_DEVICE);
}
+ idma->dma_addr = idma->dma.sg->dma_address;
+ idma->dma_len = idma->dma.sg->length;
+
iomd_writeb(DMA_CR_C, dma_base + CR);
idma->state = DMA_ST_AB;
}
--
2.7.4
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2019-05-20 14:47 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-20 14:46 [PATCH 0/8] Resurect RiscPC support Russell King - ARM Linux admin
2019-05-20 14:46 ` [PATCH 1/8] ARM: riscpc: replace gettimeoffset() with clocksource Russell King
2019-05-20 14:46 ` [PATCH 2/8] ARM: riscpc: fix lack of keyboard interrupts after irq conversion Russell King
2019-05-20 14:47 ` [PATCH 3/8] ARM: riscpc: fix ecard printing Russell King
2019-05-20 14:47 ` Russell King [this message]
2019-05-20 14:47 ` [PATCH 5/8] ARM: riscpc: dma: eliminate "cur_sg" scatterlist usage Russell King
2019-05-20 14:47 ` [PATCH 6/8] ARM: riscpc: dma: make state a local variable Russell King
2019-05-20 14:47 ` [PATCH 7/8] ARM: riscpc: dma: improve address/length writing Russell King
2019-05-20 14:47 ` [PATCH 8/8] ARM: riscpc: dma: use __iomem pointers for writing DMA Russell King
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=E1hSjZF-0000Y2-CA@rmk-PC.armlinux.org.uk \
--to=rmk+kernel@armlinux.org.uk \
--cc=linux-arm-kernel@lists.infradead.org \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.