RE: [PATCH net-next v1 3/4] net: stmmac: Add support for TX/RX channel interrupt

[Swee, Leong Ching]

> -----Original Message-----
> From: Serge Semin <fancer.lancer@xxxxxxxxx>
> Sent: Saturday, December 23, 2023 5:49 AM
> To: Swee, Leong Ching <leong.ching.swee@xxxxxxxxx>
> Cc: Maxime Coquelin <mcoquelin.stm32@xxxxxxxxx>; Alexandre Torgue
> <alexandre.torgue@xxxxxxxxxxx>; Jose Abreu <joabreu@xxxxxxxxxxxx>;
> David S . Miller <davem@xxxxxxxxxxxxx>; Eric Dumazet
> <edumazet@xxxxxxxxxx>; Jakub Kicinski <kuba@xxxxxxxxxx>; Paolo Abeni
> <pabeni@xxxxxxxxxx>; Rob Herring <robh+dt@xxxxxxxxxx>; Krzysztof
> Kozlowski <krzysztof.kozlowski+dt@xxxxxxxxxx>; Conor Dooley
> <conor+dt@xxxxxxxxxx>; Giuseppe Cavallaro <peppe.cavallaro@xxxxxx>;
> linux-stm32@xxxxxxxxxxxxxxxxxxxxxxxxxxxx; linux-arm-
> kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> netdev@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; Teoh Ji Sheng
> <ji.sheng.teoh@xxxxxxxxx>
> Subject: Re: [PATCH net-next v1 3/4] net: stmmac: Add support for TX/RX
> channel interrupt
> 
> On Fri, Dec 22, 2023 at 01:44:50PM +0800, Leong Ching Swee wrote:
> > From: Swee Leong Ching <leong.ching.swee@xxxxxxxxx>
> >
> > Enable TX/RX channel interrupt registration for MAC that interrupts
> > CPU through shared peripheral interrupt (SPI).
> >
> > Per channel interrupts and interrupt-names are registered through,
> > Eg: 4 tx and 4 rx channels:
> > interrupts = <GIC_SPI 100 IRQ_TYPE_LEVEL_HIGH>,
> >              <GIC_SPI 101 IRQ_TYPE_LEVEL_HIGH>,
> >              <GIC_SPI 102 IRQ_TYPE_LEVEL_HIGH>,
> >              <GIC_SPI 103 IRQ_TYPE_LEVEL_HIGH>;
> >              <GIC_SPI 104 IRQ_TYPE_LEVEL_HIGH>;
> >              <GIC_SPI 105 IRQ_TYPE_LEVEL_HIGH>;
> >              <GIC_SPI 106 IRQ_TYPE_LEVEL_HIGH>;
> >              <GIC_SPI 107 IRQ_TYPE_LEVEL_HIGH>; interrupt-names =
> > "dma_tx0",
> >                   "dma_tx1",
> >                   "dma_tx2",
> >                   "dma_tx3",
> >                   "dma_rx0",
> >                   "dma_rx1",
> >                   "dma_rx2",
> >                   "dma_rx3";
> >
> > Signed-off-by: Teoh Ji Sheng <ji.sheng.teoh@xxxxxxxxx>
> > Signed-off-by: Swee Leong Ching <leong.ching.swee@xxxxxxxxx>
> > ---
> >  .../ethernet/stmicro/stmmac/stmmac_platform.c | 24
> > +++++++++++++++++++
> >  1 file changed, 24 insertions(+)
> >
> > diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> > b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> > index 70eadc83ca68..f857907f13a0 100644
> > --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> > +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> > @@ -710,6 +710,8 @@
> EXPORT_SYMBOL_GPL(devm_stmmac_probe_config_dt);
> >  int stmmac_get_platform_resources(struct platform_device *pdev,
> >  				  struct stmmac_resources *stmmac_res)  {
> 
> > +	char irq_name[8];
> 
> By DW XGMAC v2.x IP-core design there can be up to 16 Tx channels and
> 12 Rx channels. Thus it's better to set irq_name size being at least
> (strlen("dma_tx16") + 1) == 9 beforehand since you are adding this code
> anyway and for some reason didn't consider to pick the Jisheng'
> patch up which fixed the MTL_MAX_TX_QUEUES/MTL_MAX_RX_QUEUES
> macros.
> 
I only have 8 channels tx/rx dma irq setup, so I could not test 16 channels
Patch. Will update to 9 in v2.
> > +	int i;
> 
> Please add an empty line between the variables declaration and the next
> statement.
> 
Thanks. Will update this in v2.
> >  	memset(stmmac_res, 0, sizeof(*stmmac_res));
> >
> >  	/* Get IRQ information early to have an ability to ask for deferred
> > @@ -719,6 +721,28 @@ int stmmac_get_platform_resources(struct
> platform_device *pdev,
> >  	if (stmmac_res->irq < 0)
> >  		return stmmac_res->irq;
> >
> 
> > +	/* For RX Channel */
> > +	for (i = 0; i < MTL_MAX_RX_QUEUES; i++) {
> > +		snprintf(irq_name, sizeof(irq_name), "dma_rx%i", i);
> > +		stmmac_res->rx_irq[i] =
> platform_get_irq_byname_optional(pdev, irq_name);
> > +		if (stmmac_res->rx_irq[i] < 0) {
> > +			if (stmmac_res->rx_irq[i] == -EPROBE_DEFER)
> > +				return -EPROBE_DEFER;
> > +			break;
> > +		}
> > +	}
> 
> What about:
> 
> +	/* Get optional Tx/Rx DMA per-channel IRQs, which otherwise
> +	 * are supposed to be delivered via the common MAC IRQ line
> +	 */
> +	for (i = 0; i < MTL_MAX_RX_QUEUES; i++) {
> +		snprintf(irq_name, sizeof(irq_name), "dma_rx%i", i);
> +		irq = platform_get_irq_byname_optional(pdev, irq_name);
> +		if (irq == -EPROBE_DEFER)
> +			return irq;
> +		else if (irq < 0)
> +			break;
> +
> +		stmmac_res->rx_irq[i] = irq;
> +	}
> 
> It's cleaner a bit with less indentations and doesn't pollute rx_irq[]/tx_irq[]
> arrays with the error numbers.
> 
Sure, will update this in v2.
> > +
> > +	/* For TX Channel */
> > +	for (i = 0; i < MTL_MAX_TX_QUEUES; i++) {
> > +		snprintf(irq_name, sizeof(irq_name), "dma_tx%i", i);
> > +		stmmac_res->tx_irq[i] =
> platform_get_irq_byname_optional(pdev, irq_name);
> > +		if (stmmac_res->tx_irq[i] < 0) {
> > +			if (stmmac_res->rx_irq[i] == -EPROBE_DEFER)
> > +				return -EPROBE_DEFER;
> > +			break;
> > +		}
> > +	}
> > +
> 
> Please move the Tx/Rx IRQs getting loops to the bottom of the
> stmmac_get_platform_resources() method. Thus the order of the IRQs
> getting would be the same as the order of the IRQs requests implemented in
> the stmmac_request_irq_multi_msi() and
> stmmac_request_irq_single() methods.
> 
> -Serge(y)
> 
Will move those methods to bottom in v2.
> >  	/* On some platforms e.g. SPEAr the wake up irq differs from the
> mac irq
> >  	 * The external wake up irq can be passed through the platform code
> >  	 * named as "eth_wake_irq"
> > --
> > 2.34.1
> >
> >