Messages in this thread | | | Date | Thu, 25 Apr 2013 10:29:30 +0100 | From | Lee Jones <> | Subject | Re: [PATCH 13/32] dmaengine: ste_dma40: Calculate number of logical channels from physical ones |
| |
On Thu, 25 Apr 2013, Linus Walleij wrote:
> On Thu, Apr 18, 2013 at 12:11 PM, Lee Jones <lee.jones@linaro.org> wrote: > > > This change will cost ~25KB of memory, but it's worth the trade-off, > > as it removes a great deal of overhead. It means that instead of only > > allocating memory for the logical channels in use, it does so for all > > available ones, which is 32 per physical channel. However, this now > > means we can remove some platform data and we don't have to worry > > about adding vendor specific variables to Device Tree. > > > > Cc: Vinod Koul <vinod.koul@intel.com> > > Cc: Dan Williams <djbw@fb.com> > > Cc: Per Forlin <per.forlin@stericsson.com> > > Cc: Rabin Vincent <rabin@rab.in> > > Signed-off-by: Lee Jones <lee.jones@linaro.org> > > (...) > > static struct stedma40_platform_data dma40_plat_data = { > > - .dev_len = DB8500_DMA_NR_DEV, > > So that was set to 64 in the platform... > > > - /* Count the number of logical channels in use */ > > - for (i = 0; i < plat_data->dev_len; i++) > > - if (plat_data->dev_rx[i] != 0) > > - num_log_chans++; > > - > > - for (i = 0; i < plat_data->dev_len; i++) > > - if (plat_data->dev_tx[i] != 0) > > - num_log_chans++; > > And I guess this code snippet made it go down to <= 32 all the time, > correct?
However many were described in dma40_[rx|tx]_map, yes.
> Just want to understand it before I ACK. (The idea is sound.) > > I notice there is no check whatsoever of the bounds of > plat_data->dev_[rx|tx] but that is a different problem I guess...
The array is going away anyway, so we don't need to threat.
-- Lee Jones Linaro ST-Ericsson Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |