PCI: add pci_try_set_mwi
As suggested by Andrew, add pci_try_set_mwi(), which does not require
return-value checking.
- add pci_try_set_mwi() without __must_check
- make it return 0 on success, errno if the "try" failed or error
- review callers
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/Documentation/pci.txt b/Documentation/pci.txt
index 7d3da30..7754f5a 100644
--- a/Documentation/pci.txt
+++ b/Documentation/pci.txt
@@ -296,7 +296,10 @@
call pci_set_mwi(). This enables the PCI_COMMAND bit for Mem-Wr-Inval
and also ensures that the cache line size register is set correctly.
Check the return value of pci_set_mwi() as not all architectures
-or chip-sets may support Memory-Write-Invalidate.
+or chip-sets may support Memory-Write-Invalidate. Alternatively,
+if Mem-Wr-Inval would be nice to have but is not required, call
+pci_try_set_mwi() to have the system do its best effort at enabling
+Mem-Wr-Inval.
3.2 Request MMIO/IOP resources
diff --git a/drivers/ata/pata_cs5530.c b/drivers/ata/pata_cs5530.c
index 3fca589..68f150a 100644
--- a/drivers/ata/pata_cs5530.c
+++ b/drivers/ata/pata_cs5530.c
@@ -266,7 +266,7 @@
}
pci_set_master(cs5530_0);
- pci_set_mwi(cs5530_0);
+ pci_try_set_mwi(cs5530_0);
/*
* Set PCI CacheLineSize to 16-bytes:
diff --git a/drivers/ide/pci/cs5530.c b/drivers/ide/pci/cs5530.c
index 1eec1f3..b5c00d1 100644
--- a/drivers/ide/pci/cs5530.c
+++ b/drivers/ide/pci/cs5530.c
@@ -236,7 +236,7 @@
*/
pci_set_master(cs5530_0);
- pci_set_mwi(cs5530_0);
+ pci_try_set_mwi(cs5530_0);
/*
* Set PCI CacheLineSize to 16-bytes:
diff --git a/drivers/net/cassini.c b/drivers/net/cassini.c
index 805924f..f6e4030 100644
--- a/drivers/net/cassini.c
+++ b/drivers/net/cassini.c
@@ -4917,13 +4917,13 @@
pci_cmd &= ~PCI_COMMAND_SERR;
pci_cmd |= PCI_COMMAND_PARITY;
pci_write_config_word(pdev, PCI_COMMAND, pci_cmd);
- if (pci_set_mwi(pdev))
+ if (pci_try_set_mwi(pdev))
printk(KERN_WARNING PFX "Could not enable MWI for %s\n",
pci_name(pdev));
/*
* On some architectures, the default cache line size set
- * by pci_set_mwi reduces perforamnce. We have to increase
+ * by pci_try_set_mwi reduces perforamnce. We have to increase
* it for this case. To start, we'll print some configuration
* data.
*/
diff --git a/drivers/net/starfire.c b/drivers/net/starfire.c
index 786d4b9..2f69d5c 100644
--- a/drivers/net/starfire.c
+++ b/drivers/net/starfire.c
@@ -740,7 +740,7 @@
pci_set_master(pdev);
/* enable MWI -- it vastly improves Rx performance on sparc64 */
- pci_set_mwi(pdev);
+ pci_try_set_mwi(pdev);
#ifdef ZEROCOPY
/* Starfire can do TCP/UDP checksumming */
diff --git a/drivers/net/tulip/tulip_core.c b/drivers/net/tulip/tulip_core.c
index 1a9e911..7dcd138 100644
--- a/drivers/net/tulip/tulip_core.c
+++ b/drivers/net/tulip/tulip_core.c
@@ -1155,7 +1155,7 @@
/* set or disable MWI in the standard PCI command bit.
* Check for the case where mwi is desired but not available
*/
- if (csr0 & MWI) pci_set_mwi(pdev);
+ if (csr0 & MWI) pci_try_set_mwi(pdev);
else pci_clear_mwi(pdev);
/* read result from hardware (in case bit refused to enable) */
diff --git a/drivers/net/wireless/prism54/islpci_hotplug.c b/drivers/net/wireless/prism54/islpci_hotplug.c
index 25d6c80..af2e4f2 100644
--- a/drivers/net/wireless/prism54/islpci_hotplug.c
+++ b/drivers/net/wireless/prism54/islpci_hotplug.c
@@ -166,8 +166,7 @@
pci_set_master(pdev);
/* enable MWI */
- if (!pci_set_mwi(pdev))
- printk(KERN_INFO "%s: pci_set_mwi(pdev) succeeded\n", DRV_NAME);
+ pci_try_set_mwi(pdev);
/* setup the network device interface and its structure */
if (!(ndev = islpci_setup(pdev))) {
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index d9fc1bd..35fa30a 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1186,6 +1186,11 @@
return 0;
}
+int pci_try_set_mwi(struct pci_dev *dev)
+{
+ return 0;
+}
+
void pci_clear_mwi(struct pci_dev *dev)
{
}
@@ -1242,9 +1247,7 @@
* pci_set_mwi - enables memory-write-invalidate PCI transaction
* @dev: the PCI device for which MWI is enabled
*
- * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND,
- * and then calls @pcibios_set_mwi to do the needed arch specific
- * operations or a generic mwi-prep function.
+ * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND.
*
* RETURNS: An appropriate -ERRNO error value on error, or zero for success.
*/
@@ -1260,7 +1263,8 @@
pci_read_config_word(dev, PCI_COMMAND, &cmd);
if (! (cmd & PCI_COMMAND_INVALIDATE)) {
- pr_debug("PCI: Enabling Mem-Wr-Inval for device %s\n", pci_name(dev));
+ pr_debug("PCI: Enabling Mem-Wr-Inval for device %s\n",
+ pci_name(dev));
cmd |= PCI_COMMAND_INVALIDATE;
pci_write_config_word(dev, PCI_COMMAND, cmd);
}
@@ -1269,6 +1273,21 @@
}
/**
+ * pci_try_set_mwi - enables memory-write-invalidate PCI transaction
+ * @dev: the PCI device for which MWI is enabled
+ *
+ * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND.
+ * Callers are not required to check the return value.
+ *
+ * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
+ */
+int pci_try_set_mwi(struct pci_dev *dev)
+{
+ int rc = pci_set_mwi(dev);
+ return rc;
+}
+
+/**
* pci_clear_mwi - disables Memory-Write-Invalidate for device dev
* @dev: the PCI device to disable
*
@@ -1600,6 +1619,7 @@
EXPORT_SYMBOL(pci_request_selected_regions);
EXPORT_SYMBOL(pci_set_master);
EXPORT_SYMBOL(pci_set_mwi);
+EXPORT_SYMBOL(pci_try_set_mwi);
EXPORT_SYMBOL(pci_clear_mwi);
EXPORT_SYMBOL_GPL(pci_intx);
EXPORT_SYMBOL(pci_set_dma_mask);
diff --git a/drivers/scsi/lpfc/lpfc_init.c b/drivers/scsi/lpfc/lpfc_init.c
index dcb4ba0..955b2e4 100644
--- a/drivers/scsi/lpfc/lpfc_init.c
+++ b/drivers/scsi/lpfc/lpfc_init.c
@@ -1578,10 +1578,7 @@
INIT_LIST_HEAD(&phba->fc_nodes);
pci_set_master(pdev);
- retval = pci_set_mwi(pdev);
- if (retval)
- dev_printk(KERN_WARNING, &pdev->dev,
- "Warning: pci_set_mwi returned %d\n", retval);
+ pci_try_set_mwi(pdev);
if (pci_set_dma_mask(phba->pcidev, DMA_64BIT_MASK) != 0)
if (pci_set_dma_mask(phba->pcidev, DMA_32BIT_MASK) != 0)
diff --git a/drivers/usb/gadget/net2280.c b/drivers/usb/gadget/net2280.c
index d975ecf..00fda33 100644
--- a/drivers/usb/gadget/net2280.c
+++ b/drivers/usb/gadget/net2280.c
@@ -2964,7 +2964,7 @@
, &dev->pci->pcimstctl);
/* erratum 0115 shouldn't appear: Linux inits PCI_LATENCY_TIMER */
pci_set_master (pdev);
- pci_set_mwi (pdev);
+ pci_try_set_mwi (pdev);
/* ... also flushes any posted pci writes */
dev->chiprev = get_idx_reg (dev->regs, REG_CHIPREV) & 0xffff;
diff --git a/include/linux/pci.h b/include/linux/pci.h
index a6657b7..a5602e2 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -545,6 +545,7 @@
int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state);
#define HAVE_PCI_SET_MWI
int __must_check pci_set_mwi(struct pci_dev *dev);
+int pci_try_set_mwi(struct pci_dev *dev);
void pci_clear_mwi(struct pci_dev *dev);
void pci_intx(struct pci_dev *dev, int enable);
void pci_msi_off(struct pci_dev *dev);
