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From: Grant Likely <grant.likely@secretlab.ca>
To: Mike Qiu <qiudayu@linux.vnet.ibm.com>,
	linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Cc: tglx@linutronix.de, Mike Qiu <qiudayu@linux.vnet.ibm.com>
Subject: Re: [PATCH 1/3] irq: Set multiple MSI descriptor data for multiple IRQs
Date: Thu, 06 Jun 2013 00:03:08 +0100	[thread overview]
Message-ID: <20130605230308.8CC093E10E4@localhost> (raw)
In-Reply-To: <1358235536-32741-2-git-send-email-qiudayu@linux.vnet.ibm.com>

On Tue, 15 Jan 2013 15:38:54 +0800, Mike Qiu <qiudayu@linux.vnet.ibm.com> wrote:
> Multiple MSI only requires the IRQ in msi_desc entry to be set as
> the value of irq_base.
> 
> This patch implements the above mentioned technique.
> 
> Signed-off-by: Mike Qiu <qiudayu@linux.vnet.ibm.com>

Hi Mike,

question below...

> ---
> +int irq_set_multiple_msi_desc(unsigned int irq_base, unsigned int nvec,
> +				struct msi_desc *entry)
> +{
> +	unsigned long flags, i;
> +	struct irq_desc *desc;
> +
> +	for (i = 0; i < nvec; i++) {
> +		desc = irq_get_desc_lock(irq_base + i, &flags,
> +					IRQ_GET_DESC_CHECK_GLOBAL);
> +		if (!desc)
> +			return -EINVAL;
> +		desc->irq_data.msi_desc = entry;
> +		if (i == 0 && entry)
> +			entry->irq = irq_base;

It's not clear to me why this code only sets the irq value for the first
desc. Why don't the other descs in the array want (irq_base + i) here? A
comment describing what is going on would be appropriate and helpful.

g.

  reply	other threads:[~2013-06-05 23:03 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-01-15  7:38 [PATCH 0/3] Enable multiple MSI feature in pSeries Mike Qiu
2013-01-15  7:38 ` [PATCH 1/3] irq: Set multiple MSI descriptor data for multiple IRQs Mike Qiu
2013-06-05 23:03   ` Grant Likely [this message]
2013-01-15  7:38 ` [PATCH 2/3] irq: Add hw continuous IRQs map to virtual continuous IRQs support Mike Qiu
2013-03-05  2:23   ` Michael Ellerman
2013-03-05  7:19     ` Mike Qiu
2013-03-06  3:54       ` Michael Ellerman
2013-03-06  5:34         ` Mike Qiu
2013-03-06  5:42           ` Michael Ellerman
2013-03-06  7:02             ` Mike Qiu
2013-03-05  2:41   ` Paul Mundt
2013-03-05  7:44     ` Mike Qiu
2013-01-15  7:38 ` [PATCH 3/3] powerpc/pci: Enable pSeries multiple MSI feature Mike Qiu
2013-01-31  2:10 ` [PATCH 0/3] Enable multiple MSI feature in pSeries Mike
2013-02-04  3:23 ` Michael Ellerman
2013-02-04  3:49   ` Mike Qiu
2013-02-04  5:56     ` Michael Ellerman
2013-02-04  6:43       ` Mike Qiu
2013-03-01  3:07 ` Mike
2013-03-01  3:08 ` Mike
2013-03-01  3:54   ` Michael Ellerman
2013-03-04  3:14     ` Mike Qiu
2013-03-05  0:28       ` Michael Ellerman
2013-05-21 14:45 ` Alexander Gordeev
2013-05-22  0:15   ` Benjamin Herrenschmidt
2013-05-22  6:16     ` Mike Qiu
2013-05-22  5:57   ` Mike Qiu

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