hollalinux
/
linux-sg2042
mirror of https://github.com/sophgo/linux-riscv.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

ARM: riscpc: fix DMA 

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: fa4e998999 ("[ARM] dma: RiscPC: don't modify DMA SG entries")
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
This commit is contained in:
Russell King 2019-05-02 17:19:18 +01:00
parent e89e261365
commit ffd9a1ba9f
1 changed files with 4 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
arch/arm/mach-rpc/dma.c
View File

@ -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;
}