[PATCH 05/16] megaraid: clean up unnecessary MSI/MSI-X capability find

[PATCH 05/16] megaraid: clean up unnecessary MSI/MSI-X capability find

[Yijing Wang]

PCI core will initialize device MSI/MSI-X capability in
pci_msi_init_pci_dev(). So device driver should use
pci_dev->msi_cap/msix_cap to determine whether the device
support MSI/MSI-X instead of using
pci_find_capability(pci_dev, PCI_CAP_ID_MSI/MSIX).
Access to PCIe device config space again will consume more time.

Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Cc: Neela Syam Kolli <megaraidlinux@lsi.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: linux-scsi@vger.kernel.org
---
 drivers/scsi/megaraid/megaraid_sas_base.c |    9 ++++-----
 1 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c
index 0177295..ad8fc44 100644
--- a/drivers/scsi/megaraid/megaraid_sas_base.c
+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
@@ -4072,21 +4072,20 @@ fail_set_dma_mask:
 static int megasas_probe_one(struct pci_dev *pdev,
 			     const struct pci_device_id *id)
 {
-	int rval, pos, i, j;
+	int rval, i, j;
 	struct Scsi_Host *host;
 	struct megasas_instance *instance;
 	u16 control = 0;
 
 	/* Reset MSI-X in the kdump kernel */
 	if (reset_devices) {
-		pos = pci_find_capability(pdev, PCI_CAP_ID_MSIX);
-		if (pos) {
-			pci_read_config_word(pdev, pos + PCI_MSIX_FLAGS,
+		if (pdev->msix_cap) {
+			pci_read_config_word(pdev, pdev->msix_cap + PCI_MSIX_FLAGS,
 					     &control);
 			if (control & PCI_MSIX_FLAGS_ENABLE) {
 				dev_info(&pdev->dev, "resetting MSI-X\n");
 				pci_write_config_word(pdev,
-						      pos + PCI_MSIX_FLAGS,
+						      pdev->msix_cap + PCI_MSIX_FLAGS,
 						      control &
 						      ~PCI_MSIX_FLAGS_ENABLE);
 			}
-- 
1.7.1

RE: [PATCH 05/16] megaraid: clean up unnecessary MSI/MSI-X capability find

[Saxena, Sumit]

>-----Original Message-----
>From: Yijing Wang [mailto:wangyijing@huawei.com]
>Sent: Thursday, August 08, 2013 6:38 PM
>To: James E.J. Bottomley
>Cc: Hanjun Guo; jiang.liu@huawei.com; Yijing Wang; DL-MegaRAID Linux;
>linux-scsi@vger.kernel.org
>Subject: [PATCH 05/16] megaraid: clean up unnecessary MSI/MSI-X
>capability find
>
>PCI core will initialize device MSI/MSI-X capability in
>pci_msi_init_pci_dev(). So device driver should use pci_dev-
>>msi_cap/msix_cap to determine whether the device support MSI/MSI-X
>instead of using pci_find_capability(pci_dev, PCI_CAP_ID_MSI/MSIX).
>Access to PCIe device config space again will consume more time.
>
>Signed-off-by: Yijing Wang <wangyijing@huawei.com>
>Cc: Neela Syam Kolli <megaraidlinux@lsi.com>
>Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
>Cc: linux-scsi@vger.kernel.org
>---
> drivers/scsi/megaraid/megaraid_sas_base.c |    9 ++++-----
> 1 files changed, 4 insertions(+), 5 deletions(-)
>
>diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c
>b/drivers/scsi/megaraid/megaraid_sas_base.c
>index 0177295..ad8fc44 100644
>--- a/drivers/scsi/megaraid/megaraid_sas_base.c
>+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
>@@ -4072,21 +4072,20 @@ fail_set_dma_mask:
> static int megasas_probe_one(struct pci_dev *pdev,
> 			     const struct pci_device_id *id)  {
>-	int rval, pos, i, j;
>+	int rval, i, j;
> 	struct Scsi_Host *host;
> 	struct megasas_instance *instance;
> 	u16 control = 0;
>
> 	/* Reset MSI-X in the kdump kernel */
> 	if (reset_devices) {
>-		pos = pci_find_capability(pdev, PCI_CAP_ID_MSIX);
>-		if (pos) {
>-			pci_read_config_word(pdev, pos + PCI_MSIX_FLAGS,
>+		if (pdev->msix_cap) {
>+			pci_read_config_word(pdev, pdev->msix_cap +
>PCI_MSIX_FLAGS,
> 					     &control);
> 			if (control & PCI_MSIX_FLAGS_ENABLE) {
> 				dev_info(&pdev->dev, "resetting MSI-X\n");
> 				pci_write_config_word(pdev,
>-						      pos + PCI_MSIX_FLAGS,
>+						      pdev->msix_cap +
>PCI_MSIX_FLAGS,
> 						      control &
> 						      ~PCI_MSIX_FLAGS_ENABLE);
> 			}
>--
>1.7.1
>
>
Acked-by: Sumit Saxena <sumit.saxena@lsi.com>


Sumit

Re: [PATCH 05/16] megaraid: clean up unnecessary MSI/MSI-X capability find

[Yijing Wang]

>> PCI_MSIX_FLAGS,
>> 						      control &
>> 						      ~PCI_MSIX_FLAGS_ENABLE);
>> 			}
>> --
>> 1.7.1
>>
>>
> Acked-by: Sumit Saxena <sumit.saxena@lsi.com>

Hi James,
   Can you merge this patch?

Thanks!
Yijing.


> 
> 


-- 
Thanks!
Yijing