Vinod Koul <vinod.koul@xxxxxxxxx> writes:
>> +#define DCSR_RUN BIT(31) /* Run Bit (read / write) */
>> +#define DCSR_NODESC BIT(30) /* No-Descriptor Fetch (read / write) */
>> +#define DCSR_STOPIRQEN BIT(29) /* Stop Interrupt Enable (read / write) */
>> +#define DCSR_REQPEND BIT(8) /* Request Pending (read-only) */
>> +#define DCSR_STOPSTATE BIT(3) /* Stop State (read-only) */
>> +#define DCSR_ENDINTR BIT(2) /* End Interrupt (read / write) */
>> +#define DCSR_STARTINTR BIT(1) /* Start Interrupt (read / write) */
>> +#define DCSR_BUSERR BIT(0) /* Bus Error Interrupt (read / write) */
>> +
>> +#define DCSR_EORIRQEN BIT(28) /* End of Receive Interrupt Enable (R/W) */
>> +#define DCSR_EORJMPEN BIT(27) /* Jump to next descriptor on EOR */
>> +#define DCSR_EORSTOPEN BIT(26) /* STOP on an EOR */
>> +#define DCSR_SETCMPST BIT(25) /* Set Descriptor Compare Status */
>> +#define DCSR_CLRCMPST BIT(24) /* Clear Descriptor Compare Status */
>> +#define DCSR_CMPST BIT(10) /* The Descriptor Compare Status */
>> +#define DCSR_EORINTR BIT(9) /* The end of Receive */
> would help if these are PXA_xxx
OK, for v4.
>> +
>> +/*
>> + * Requestor lines are mapped as :
>> + * - lines 0 to 63 : DRCMR(line) = 0x100 + line * 4
>> + * - lines 64 to +oo : DRCMR(line) = 0x1000 + line * 4
>> + */
>> +#define DRCMR(n) ((((n) < 64) ? 0x0100 : 0x1100) + (((n) & 0x3f) << 2))
> This is hard to read, why not make this a function?
Yes, why not. For v4.
>> +static int pxad_alloc_chan_resources(struct dma_chan *dchan)
>> +{
>> + struct pxad_chan *chan = to_pxad_chan(dchan);
>> + struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
>> +
>> + if (chan->desc_pool)
>> + return 1;
>> +
>> + chan->desc_pool = dma_pool_create(dma_chan_name(dchan),
>> + pdev->slave.dev,
>> + sizeof(struct pxad_desc_hw),
>> + __alignof__(struct pxad_desc_hw),
> why __alignof__ and why not simple say sizeof(struct pxad_desc_hw) to align
> the pool for this struct.
Because it's not the size of the struct which makes its alignement requirement,
but it's declared alignement (see pxad_desc_hw declaration, especially the
__aligned((16)) part). Would the requirement have been of 32 bytes for the same
structure size (because of a IP hardware designer whim), I would only need to
modify the pxad_desc_hw structure declaration.
> Also you have given the descriptor size here for pool size, which sounds odd
> and ideally you would like to request a large pool for channel for allocating
> multiple desc
Euh how so ? dma_pool_create() takes as its third argument the size of one
unitary block, ie. one pxad_desc_hw, which is of sizeof(struct pxad_desc_hw) bytes.
You probably know that dma_pool_create() allocates per pages, ie. multiple
pxad_desc_hw will be allocated at once.
>> +static struct pxad_desc_sw *
>> +pxad_alloc_desc(struct pxad_chan *chan, unsigned int nb_hw_desc)
>> +{
>> + struct pxad_desc_sw *sw_desc;
>> + dma_addr_t dma;
>> + int i;
>> +
>> + sw_desc = kzalloc(sizeof(*sw_desc) +
>> + nb_hw_desc * sizeof(struct pxad_desc_hw *),
>> + GFP_ATOMIC);
> GFP_NOWAIT
Ok.
>> + if (!sw_desc)
>> + return NULL;
>> + sw_desc->desc_pool = chan->desc_pool;
>> +
>> + for (i = 0; i < nb_hw_desc; i++) {
>> + sw_desc->hw_desc[i] = dma_pool_alloc(sw_desc->desc_pool,
>> + GFP_ATOMIC, &dma);
> GFP_NOWAIT
Ok.
--
Robert
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