| Date | Thu, 25 Apr 2013 11:13:16 +0200 | Subject | Re: [PATCH 13/32] dmaengine: ste_dma40: Calculate number of logical channels from physical ones | From | Linus Walleij <> |
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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?
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...
Yours, Linus Walleij
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