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From: Christoph Hellwig <hch@lst.de>
To: Emmanuel Benisty <benisty.e@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>,
	tj@kernel.org, linux-ide@vger.kernel.org,
	linux-pci@vger.kernel.org
Subject: Re: use pci_alloc_irq_vectors issues
Date: Mon, 17 Oct 2016 21:28:58 +0200	[thread overview]
Message-ID: <20161017192858.GA25429@lst.de> (raw)
In-Reply-To: <CA+i8gK+UfUmKtYpXH1cObd3_5WWje397pgQqW5SmwFg8ms+aLw@mail.gmail.com>

Hi Emmanuel,

I think I have an idea now - we are accidentally hitting the per-port
MSI vector case because your SSD only has one AHCI "port".  Can you
try the below patch:

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index ba5f11c..3c2f92b 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1413,6 +1413,7 @@ static int ahci_init_msi(struct pci_dev *pdev, unsigned int n_ports,
 	if (hpriv->flags & AHCI_HFLAG_NO_MSI)
 		return -ENODEV;
 
+	if (n_ports > 1) {
 	/*
 	 * If number of MSIs is less than number of ports then Sharing Last
 	 * Message mode could be enforced. In this case assume that advantage
@@ -1434,6 +1435,7 @@ static int ahci_init_msi(struct pci_dev *pdev, unsigned int n_ports,
 		printk(KERN_INFO "ahci: MRSM is on, fallback to single MSI\n");
 		pci_free_irq_vectors(pdev);
 	}
+	}
 
 	/*
 	 * -ENOSPC indicated we don't have enough vectors.  Don't bother trying

  reply	other threads:[~2016-10-17 19:29 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CA+i8gKJ1BnOE8tOzxfbFJcG1qa9XchiDBQSGZUHUOch6byi+tQ@mail.gmail.com>
2016-10-17  8:01 ` use pci_alloc_irq_vectors issues Christoph Hellwig
2016-10-17  8:10   ` Emmanuel Benisty
2016-10-17  9:26     ` Christoph Hellwig
2016-10-17  9:33       ` Emmanuel Benisty
2016-10-17 10:34         ` Christoph Hellwig
2016-10-17 11:12           ` Emmanuel Benisty
2016-10-17 12:02             ` Christoph Hellwig
2016-10-17 12:48               ` Emmanuel Benisty
2016-10-17 19:28                 ` Christoph Hellwig [this message]
2016-10-17 20:51                   ` Emmanuel Benisty
2016-10-17 20:55                     ` Christoph Hellwig

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