Messages in this thread | | | Date | Tue, 29 Apr 2014 15:45:08 -0400 (EDT) | Subject | Re: [PATCH v2 1/1] Driver for Beckhoff CX5020 EtherCAT master module. | From | David Miller <> |
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From: Darek Marcinkiewicz <reksio@newterm.pl> Date: Mon, 28 Apr 2014 07:36:58 +0200
> +void *ec_bh_alloc_dma_mem(struct bh_priv *priv, > + int channel, > + u8 **buf, > + dma_addr_t *phys, > + dma_addr_t *phys_buf, > + size_t *len) { > + u32 mask; > + int offset = channel * DMA_CHAN_SIZE + DMA_CHAN_OFFSET; > + > + iowrite32(0xffffffff, priv->dma_io + offset); > + > + mask = ioread32(priv->dma_io + offset); > + mask &= 0xfffffffc; > + dev_info(PRIV_TO_DEV(priv), > + "Read mask %x for channel %d\n", > + mask, channel); > + *len = ~mask + 1; > + > + dev_info(PRIV_TO_DEV(priv), > + "Allocating %d bytes for channel %d", > + (int)*len, channel); > + *buf = pci_alloc_consistent(priv->dev, > + *len * 2, > + phys_buf);
This is really confusing, the log message says that it allocates "*len" bytes, but actually you are allocating "*len * 2" bytes as per the arguments you are passing into pci_alloc_consistent.
Either one or the other is wrong, and if "*len * 2" is the correct size then it should be explained why you're doubling this value but providing just plain "*len" to the caller.
All of these *len values seem to be doubled over and over again, in the memset() calls, in the pci_free_consistent() calls during resource release on probe error and driver shutdown.
Why not just assign X * 2 to *len and get rid of this doubling all over the place?
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