On 08.10.2015 11:51, Robin Gong wrote:
On Thu, Oct 01, 2015 at 12:34:54AM +0000, Bondarenko, Anton wrote:
On 30.09.2015 10:35, Robin Gong wrote:
On Fri, Sep 25, 2015 at 07:57:10PM +0200, Anton Bondarenko wrote:
@@ -91,11 +91,15 @@ struct spi_imx_data {
struct completion xfer_done;
void __iomem *base;
+ unsigned long base_phys;
+
struct clk *clk_per;
struct clk *clk_ipg;
unsigned long spi_clk;
unsigned int spi_bus_clk;
+ unsigned int bpw_w;
+
It's better to change bytes_per_word for clear understanding,since bpw in spi means
bits_per_word...
Agree. Fixed in V3
unsigned int count;
void (*tx)(struct spi_imx_data *);
void (*rx)(struct spi_imx_data *);
@@ -201,9 +205,13 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
struct spi_transfer *transfer)
{
struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
+ unsigned int bpw_w = transfer->bits_per_word;
- if (spi_imx->dma_is_inited &&
- (transfer->len > spi_imx->wml * sizeof(u32)))
+ if (!bpw_w)
+ bpw_w = spi->bits_per_word;
+
+ bpw_w = DIV_ROUND_UP(bpw_w, 8);
+ if (spi_imx->dma_is_inited && (transfer->len > spi_imx->wml * bpw_w))
Please remove bpw_w here as I talked in the first patch.
As explained in patch1 we need to use SPI word size in calculation to decide
if we want to go with DMA or PIO mode. Just a short example:
We need to transfer 24 SPI words with BPW == 32. This will take ~ 24 PIO writes
to FIFO (and same for reads). But transfer->len will be 24*4=96 bytes.
WML is 32 SPI words. The decision will be incorrect if we do not take into account
SPI bits per word.
Yes, you are right, but I'm thinking so many 'DIV_ROUND_UP()'in your patch to
get bpw, can you centralize it or just use the 'bpw_w' in 'struct spi_imx_data'?
We can't use bpw_w from spi_imx_data because this is external callback
for SPI core and driver does not know the purpose of this call. We also
can't update current bpw_w for the same reason.
I'll add a function like this:
int spi_imx_get_bytes_per_word(int bpw)
{
return DIV_ROUND_UP(bpw, BITS_PER_BYTE);
}
return true;
return false;
}
Regards,
Anton
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