Re: [PATCH 13/32] dmaengine: ste_dma40: Calculate number of logicalchannels from physical ones

From: Lee Jones
Date: Mon Apr 22 2013 - 06:11:46 EST


On Mon, 22 Apr 2013, Vinod Koul wrote:

> On Thu, Apr 18, 2013 at 11:11:55AM +0100, Lee Jones 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@xxxxxxxxx>
> > Cc: Dan Williams <djbw@xxxxxx>
> > Cc: Per Forlin <per.forlin@xxxxxxxxxxxxxx>
> > Cc: Rabin Vincent <rabin@xxxxxx>
> > Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx>
> > ---
> > arch/arm/mach-ux500/devices-db8500.c | 1 -
> > drivers/dma/ste_dma40.c | 16 ++++++----------
> > include/linux/platform_data/dma-ste-dma40.h | 2 --
> > 3 files changed, 6 insertions(+), 13 deletions(-)
> >
> > diff --git a/arch/arm/mach-ux500/devices-db8500.c b/arch/arm/mach-ux500/devices-db8500.c
> > index 03efd4c1..2fcb8c2 100644
> > --- a/arch/arm/mach-ux500/devices-db8500.c
> > +++ b/arch/arm/mach-ux500/devices-db8500.c
> > @@ -121,7 +121,6 @@ static const dma_addr_t dma40_rx_map[DB8500_DMA_NR_DEV] = {
> > };
> >
> > static struct stedma40_platform_data dma40_plat_data = {
> > - .dev_len = DB8500_DMA_NR_DEV,
> > .dev_rx = dma40_rx_map,
> > .dev_tx = dma40_tx_map,
> > .disabled_channels = {-1},
> > diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c
> > index 7b451b2..a39ef74 100644
> > --- a/drivers/dma/ste_dma40.c
> > +++ b/drivers/dma/ste_dma40.c
> > @@ -45,6 +45,9 @@
> > #define D40_LCLA_LINK_PER_EVENT_GRP 128
> > #define D40_LCLA_END D40_LCLA_LINK_PER_EVENT_GRP
> >
> > +/* Max number of logical channels per physical channel */
> > +#define D40_MAX_LOG_CHAN_PER_PHY 32
> > +
> > /* Attempts before giving up to trying to get pages that are aligned */
> > #define MAX_LCLA_ALLOC_ATTEMPTS 256
> >
> > @@ -3197,6 +3200,8 @@ static struct d40_base * __init d40_hw_detect_init(struct platform_device *pdev)
> > else
> > num_phy_chans = 4 * (readl(virtbase + D40_DREG_ICFG) & 0x7) + 4;
> >
> > + num_log_chans = num_phy_chans * D40_MAX_LOG_CHAN_PER_PHY;
> > +
> > dev_info(&pdev->dev, "hardware revision: %d @ 0x%x with %d physical channels\n",
> > rev, res->start, num_phy_chans);
> >
> > @@ -3206,15 +3211,6 @@ static struct d40_base * __init d40_hw_detect_init(struct platform_device *pdev)
> > goto failure;
> > }
> >
> > - /* 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++;
> > -
> > base = kzalloc(ALIGN(sizeof(struct d40_base), 4) +
> > (num_phy_chans + num_log_chans + ARRAY_SIZE(dma40_memcpy_channels)) *
> > sizeof(struct d40_chan), GFP_KERNEL);
> > @@ -3282,7 +3278,7 @@ static struct d40_base * __init d40_hw_detect_init(struct platform_device *pdev)
> > * The max number of logical channels are event lines for all
> > * src devices and dst devices
> > */
> > - base->lookup_log_chans = kzalloc(plat_data->dev_len * 2 *
> > + base->lookup_log_chans = kzalloc(num_log_chans *
> you could have used devm_ helper for this.

I'll convert the entire driver over to devm_ in a latter patch.

> Acked-by: Vinod Koul <vnod.koul@xxxxxxxxx>

Thanks.

--
Lee Jones
Linaro ST-Ericsson Landing Team Lead
Linaro.org â Open source software for ARM SoCs
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