2014-04-15 09:35:40

by Alexander Gordeev

Subject: [PATCH] qlcnic: Fix MSI-X initialization code

Function qlcnic_setup_tss_rss_intr() might enter endless
loop in case pci_enable_msix() contiguously returns a
positive number of MSI-Xs that could have been allocated.
Besides, the function contains 'err = -EIO;' assignment
that never could be reached. This update fixes the
aforementioned issues.

Cc: Shahed Shaikh <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]

Signed-off-by: Alexander Gordeev <[email protected]>
---
drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c | 28 ++++++++++++---------
1 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c
index 309d056..2e615d5 100644
--- a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c
+++ b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c
@@ -670,7 +670,7 @@ int qlcnic_setup_tss_rss_intr(struct qlcnic_adapter *adapter)
else
num_msix += adapter->drv_tx_rings;

- if (adapter->drv_rss_rings > 0)
+ if (adapter->drv_rss_rings > 0)
num_msix += adapter->drv_rss_rings;
else
num_msix += adapter->drv_sds_rings;
@@ -686,19 +686,15 @@ int qlcnic_setup_tss_rss_intr(struct qlcnic_adapter *adapter)
return -ENOMEM;
}

-restore:
for (vector = 0; vector < num_msix; vector++)
adapter->msix_entries[vector].entry = vector;

+restore:
err = pci_enable_msix(pdev, adapter->msix_entries, num_msix);
- if (err == 0) {
- adapter->ahw->num_msix = num_msix;
- if (adapter->drv_tss_rings > 0)
- adapter->drv_tx_rings = adapter->drv_tss_rings;
+ if (err > 0) {
+ if (!adapter->drv_tss_rings && !adapter->drv_rss_rings)
+ return -ENOSPC;

- if (adapter->drv_rss_rings > 0)
- adapter->drv_sds_rings = adapter->drv_rss_rings;
- } else {
netdev_info(adapter->netdev,
"Unable to allocate %d MSI-X vectors, Available vectors %d\n",
num_msix, err);
@@ -716,12 +712,20 @@ restore:
"Restoring %d Tx, %d SDS rings for total %d vectors.\n",
adapter->drv_tx_rings, adapter->drv_sds_rings,
num_msix);
- goto restore;

- err = -EIO;
+ goto restore;
+ } else if (err < 0) {
+ return err;
}

- return err;
+ adapter->ahw->num_msix = num_msix;
+ if (adapter->drv_tss_rings > 0)
+ adapter->drv_tx_rings = adapter->drv_tss_rings;
+
+ if (adapter->drv_rss_rings > 0)
+ adapter->drv_sds_rings = adapter->drv_rss_rings;
+
+ return 0;
}

int qlcnic_enable_msix(struct qlcnic_adapter *adapter, u32 num_msix)
--
1.7.7.6

2014-04-15 12:07:05

by Shahed Shaikh

Subject: RE: [PATCH] qlcnic: Fix MSI-X initialization code

> -----Original Message-----
> From: Alexander Gordeev [mailto:[email protected]]
> Sent: Tuesday, April 15, 2014 3:07 PM
> To: linux-kernel
> Cc: Alexander Gordeev; Shahed Shaikh; Dept-HSG Linux NIC Dev; netdev;
> linux-pci
> Subject: [PATCH] qlcnic: Fix MSI-X initialization code
>
> Function qlcnic_setup_tss_rss_intr() might enter endless loop in case
> pci_enable_msix() contiguously returns a positive number of MSI-Xs that
> could have been allocated.
> Besides, the function contains 'err = -EIO;' assignment that never could be
> reached. This update fixes the aforementioned issues.
>
> Cc: Shahed Shaikh <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
>
> Signed-off-by: Alexander Gordeev <[email protected]>

Acked-by: Shahed Shaikh <[email protected]>

Thanks,
Shahed
> ---
> drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c | 28 ++++++++++++-------
> --
> 1 files changed, 16 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c
> b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c
> index 309d056..2e615d5 100644
> --- a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c
> +++ b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c
> @@ -670,7 +670,7 @@ int qlcnic_setup_tss_rss_intr(struct qlcnic_adapter
> *adapter)
> else
> num_msix += adapter->drv_tx_rings;
>
> - if (adapter->drv_rss_rings > 0)
> + if (adapter->drv_rss_rings > 0)
> num_msix += adapter->drv_rss_rings;
> else
> num_msix += adapter->drv_sds_rings;
> @@ -686,19 +686,15 @@ int qlcnic_setup_tss_rss_intr(struct qlcnic_adapter
> *adapter)
> return -ENOMEM;
> }
>
> -restore:
> for (vector = 0; vector < num_msix; vector++)
> adapter->msix_entries[vector].entry = vector;
>
> +restore:
> err = pci_enable_msix(pdev, adapter->msix_entries, num_msix);
> - if (err == 0) {
> - adapter->ahw->num_msix = num_msix;
> - if (adapter->drv_tss_rings > 0)
> - adapter->drv_tx_rings = adapter->drv_tss_rings;
> + if (err > 0) {
> + if (!adapter->drv_tss_rings && !adapter->drv_rss_rings)
> + return -ENOSPC;
>
> - if (adapter->drv_rss_rings > 0)
> - adapter->drv_sds_rings = adapter->drv_rss_rings;
> - } else {
> netdev_info(adapter->netdev,
> "Unable to allocate %d MSI-X vectors, Available
> vectors %d\n",
> num_msix, err);
> @@ -716,12 +712,20 @@ restore:
> "Restoring %d Tx, %d SDS rings for total %d
> vectors.\n",
> adapter->drv_tx_rings, adapter->drv_sds_rings,
> num_msix);
> - goto restore;
>
> - err = -EIO;
> + goto restore;
> + } else if (err < 0) {
> + return err;
> }
>
> - return err;
> + adapter->ahw->num_msix = num_msix;
> + if (adapter->drv_tss_rings > 0)
> + adapter->drv_tx_rings = adapter->drv_tss_rings;
> +
> + if (adapter->drv_rss_rings > 0)
> + adapter->drv_sds_rings = adapter->drv_rss_rings;
> +
> + return 0;
> }
>
> int qlcnic_enable_msix(struct qlcnic_adapter *adapter, u32 num_msix)
> --
> 1.7.7.6

2014-04-15 19:15:26

by David Miller

Subject: Re: [PATCH] qlcnic: Fix MSI-X initialization code

From: Alexander Gordeev <[email protected]>
Date: Tue, 15 Apr 2014 11:37:14 +0200

> Function qlcnic_setup_tss_rss_intr() might enter endless
> loop in case pci_enable_msix() contiguously returns a
> positive number of MSI-Xs that could have been allocated.
> Besides, the function contains 'err = -EIO;' assignment
> that never could be reached. This update fixes the
> aforementioned issues.
>
> Cc: Shahed Shaikh <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
>
> Signed-off-by: Alexander Gordeev <[email protected]>

Applied, thanks.