Re: [RFC v2 2/8] video: tegra: Add syncpoint wait and interrupts

From: Stephen Warren
Date: Thu Nov 29 2012 - 13:41:41 EST


On 11/29/2012 01:44 AM, Thierry Reding wrote:
> On Mon, Nov 26, 2012 at 03:19:08PM +0200, Terje Bergstrom wrote:

>> diff --git a/drivers/video/tegra/host/host1x/host1x_intr.c
>> b/drivers/video/tegra/host/host1x/host1x_intr.c
> [...]
>> +/* Spacing between sync registers */ +#define REGISTER_STRIDE 4
>
> Erm... no. The usual way you should be doing this is either make
> the register definitions account for the stride or use accessors
> that apply the stride. You should be doing the latter anyway to
> make accesses. For example:
>
> static inline void host1x_syncpt_writel(struct host1x *host1x,
> unsigned long value, unsigned long offset) { writel(value,
> host1x->regs + SYNCPT_BASE + offset); }
>
> static inline unsigned long host1x_syncpt_readl(struct host1x
> *host1x, unsigned long offset) { return readl(host1x->regs +
> SYNCPT_BASE + offset); }
>
> Alternatively, if you want to pass the register index instead of
> the offset, you can use just multiply the offset in that function:
>
> writel(value, host1x->regs + SYNCPT_BASE + (offset << 2));
>
> The same can also be done with the non-syncpt registers.

It seems like reasonable documentation to replace "<< 2" with "*
REGISTER_STRIDE" here.
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