On 2025-03-10 8:47 pm, Vinod Koul wrote:
On 28-02-25, 17:26, Robin Murphy wrote:+static u32 d350_get_residue(struct d350_chan *dch) +{ + u32 res, xsize, xsizehi, hi_new; + + hi_new = readl_relaxed(dch->base + CH_XSIZEHI); + do { + xsizehi = hi_new; + xsize = readl_relaxed(dch->base + CH_XSIZE); + hi_new = readl_relaxed(dch->base + CH_XSIZEHI); + } while (xsizehi != hi_new);This can go forever, lets have some limits to this loop please
Sure, in practice I doubt we're ever going to be continually preempted faster than the controller can move another 64KB of data, but I concur there's no harm in making the code easier to reason about at a glance either.
+static int d350_alloc_chan_resources(struct dma_chan *chan) +{ + struct d350_chan *dch = to_d350_chan(chan); + int ret = request_irq(dch->irq, d350_irq, IRQF_SHARED, + dev_name(&dch->vc.chan.dev->device), dch);This is interesting, any reason why the irq is allocated here? Would it be not better to do that in probe...
Well, I'd say technically the IRQ is a channel resource, and quite a few other drivers do the same... Here it's mostly so I can get the channel name - so the IRQs are nice and identifiable in /proc/interrupts - easily without making a big mess in probe, since the names don't exist until after the device is registered.
Thanks, Robin.
