Re: [PATCH] PCI: Remove pci_try_set_mwi

Heiner Kallweit
2021-03-27T23:07:04Z

On 26.03.2021 22:26, Bjorn Helgaas wrote:
> [+cc Randy, Andrew (though I'm sure you have zero interest in this
> ancient question :))]
>
> On Wed, Dec 09, 2020 at 09:31:21AM +0100, Heiner Kallweit wrote:
>> pci_set_mwi() and pci_try_set_mwi() do exactly the same, just that the
>> former one is declared as __must_check. However also some callers of
>> pci_set_mwi() have a comment that it's an optional feature. I don't
>> think there's much sense in this separation and the use of
>> __must_check. Therefore remove pci_try_set_mwi() and remove the
>> __must_check attribute from pci_set_mwi().
>> I don't expect either function to be used in new code anyway.
>
> There's not much I like better than removing things. But some
> significant thought went into adding pci_try_set_mwi() in the first
> place, so I need a little more convincing about why it's safe to
> remove it.
>

Thanks for the link to the 13 yrs old discussion. Unfortunately it
doesn't mention any real argument for the __must_check, just:

"And one of the reasons for adding the __must_check annotation is to
weed out design errors."
And the very next response in the discussion calls this a "non-argument".
Plus not mentioning what the other reasons could be.

Currently we have three ancient drivers that bail out if the call fails.
Most callers of pci_set_mwi() use the return code only to emit an
error message, but they proceed normally. Majority of users calls
pci_try_set_mwi(). And as stated in the commit message I don't expect
any new usage of pci_set_mwi().

> The argument should cite the discussion about adding it. I think one
> of the earliest conversations is here:
> https://lore.kernel.org/linux-ide/20070404213704.224128ec.randy.dunlap@oracle.com/
>
>> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
>> ---
>> patch applies on top of pci/misc for v5.11
>> ---
>> Documentation/PCI/pci.rst | 5 +----
>> drivers/ata/pata_cs5530.c | 2 +-
>> drivers/ata/sata_mv.c | 2 +-
>> drivers/dma/dw/pci.c | 2 +-
>> drivers/dma/hsu/pci.c | 2 +-
>> drivers/ide/cs5530.c | 2 +-
>> drivers/mfd/intel-lpss-pci.c | 2 +-
>> drivers/net/ethernet/adaptec/starfire.c | 2 +-
>> drivers/net/ethernet/alacritech/slicoss.c | 2 +-
>> drivers/net/ethernet/dec/tulip/tulip_core.c | 5 +----
>> drivers/net/ethernet/sun/cassini.c | 4 ++--
>> drivers/net/wireless/intersil/p54/p54pci.c | 2 +-
>> .../intersil/prism54/islpci_hotplug.c | 3 +--
>> .../wireless/realtek/rtl818x/rtl8180/dev.c | 2 +-
>> drivers/pci/pci.c | 19 -------------------
>> drivers/scsi/3w-9xxx.c | 4 ++--
>> drivers/scsi/3w-sas.c | 4 ++--
>> drivers/scsi/csiostor/csio_init.c | 2 +-
>> drivers/scsi/lpfc/lpfc_init.c | 2 +-
>> drivers/scsi/qla2xxx/qla_init.c | 8 ++++----
>> drivers/scsi/qla2xxx/qla_mr.c | 2 +-
>> drivers/tty/serial/8250/8250_lpss.c | 2 +-
>> drivers/usb/chipidea/ci_hdrc_pci.c | 2 +-
>> drivers/usb/gadget/udc/amd5536udc_pci.c | 2 +-
>> drivers/usb/gadget/udc/net2280.c | 2 +-
>> drivers/usb/gadget/udc/pch_udc.c | 2 +-
>> include/linux/pci.h | 5 ++---
>> 27 files changed, 33 insertions(+), 60 deletions(-)
>>
>> diff --git a/Documentation/PCI/pci.rst b/Documentation/PCI/pci.rst
>> index 814b40f83..120362cc9 100644
>> --- a/Documentation/PCI/pci.rst
>> +++ b/Documentation/PCI/pci.rst
>> @@ -226,10 +226,7 @@ If the PCI device can use the PCI Memory-Write-Invalidate transaction,
>> 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. 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.
>> +or chip-sets may support Memory-Write-Invalidate.
>>
>>
>> Request MMIO/IOP resources
>> diff --git a/drivers/ata/pata_cs5530.c b/drivers/ata/pata_cs5530.c
>> index ad75d02b6..8654b3ae1 100644
>> --- a/drivers/ata/pata_cs5530.c
>> +++ b/drivers/ata/pata_cs5530.c
>> @@ -214,7 +214,7 @@ static int cs5530_init_chip(void)
>> }
>>
>> pci_set_master(cs5530_0);
>> - pci_try_set_mwi(cs5530_0);
>> + pci_set_mwi(cs5530_0);
>>
>> /*
>> * Set PCI CacheLineSize to 16-bytes:
>> diff --git a/drivers/ata/sata_mv.c b/drivers/ata/sata_mv.c
>> index 664ef658a..ee37755ea 100644
>> --- a/drivers/ata/sata_mv.c
>> +++ b/drivers/ata/sata_mv.c
>> @@ -4432,7 +4432,7 @@ static int mv_pci_init_one(struct pci_dev *pdev,
>> mv_print_info(host);
>>
>> pci_set_master(pdev);
>> - pci_try_set_mwi(pdev);
>> + pci_set_mwi(pdev);
>> return ata_host_activate(host, pdev->irq, mv_interrupt, IRQF_SHARED,
>> IS_GEN_I(hpriv) ? &mv5_sht : &mv6_sht);
>> }
>> diff --git a/drivers/dma/dw/pci.c b/drivers/dma/dw/pci.c
>> index 1142aa6f8..1c20b7485 100644
>> --- a/drivers/dma/dw/pci.c
>> +++ b/drivers/dma/dw/pci.c
>> @@ -30,7 +30,7 @@ static int dw_pci_probe(struct pci_dev *pdev, const struct pci_device_id *pid)
>> }
>>
>> pci_set_master(pdev);
>> - pci_try_set_mwi(pdev);
>> + pci_set_mwi(pdev);
>>
>> ret = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
>> if (ret)
>> diff --git a/drivers/dma/hsu/pci.c b/drivers/dma/hsu/pci.c
>> index 07cc7320a..420dd3706 100644
>> --- a/drivers/dma/hsu/pci.c
>> +++ b/drivers/dma/hsu/pci.c
>> @@ -73,7 +73,7 @@ static int hsu_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>> }
>>
>> pci_set_master(pdev);
>> - pci_try_set_mwi(pdev);
>> + pci_set_mwi(pdev);
>>
>> ret = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
>> if (ret)
>> diff --git a/drivers/ide/cs5530.c b/drivers/ide/cs5530.c
>> index 5bb46e713..5d2c421ab 100644
>> --- a/drivers/ide/cs5530.c
>> +++ b/drivers/ide/cs5530.c
>> @@ -168,7 +168,7 @@ static int init_chipset_cs5530(struct pci_dev *dev)
>> */
>>
>> pci_set_master(cs5530_0);
>> - pci_try_set_mwi(cs5530_0);
>> + pci_set_mwi(cs5530_0);
>>
>> /*
>> * Set PCI CacheLineSize to 16-bytes:
>> diff --git a/drivers/mfd/intel-lpss-pci.c b/drivers/mfd/intel-lpss-pci.c
>> index 2d7c588ef..a0c3be750 100644
>> --- a/drivers/mfd/intel-lpss-pci.c
>> +++ b/drivers/mfd/intel-lpss-pci.c
>> @@ -39,7 +39,7 @@ static int intel_lpss_pci_probe(struct pci_dev *pdev,
>>
>> /* Probably it is enough to set this for iDMA capable devices only */
>> pci_set_master(pdev);
>> - pci_try_set_mwi(pdev);
>> + pci_set_mwi(pdev);
>>
>> ret = intel_lpss_probe(&pdev->dev, info);
>> if (ret)
>> diff --git a/drivers/net/ethernet/adaptec/starfire.c b/drivers/net/ethernet/adaptec/starfire.c
>> index 555299737..1dbff34c4 100644
>> --- a/drivers/net/ethernet/adaptec/starfire.c
>> +++ b/drivers/net/ethernet/adaptec/starfire.c
>> @@ -679,7 +679,7 @@ static int starfire_init_one(struct pci_dev *pdev,
>> pci_set_master(pdev);
>>
>> /* enable MWI -- it vastly improves Rx performance on sparc64 */
>> - pci_try_set_mwi(pdev);
>> + pci_set_mwi(pdev);
>>
>> #ifdef ZEROCOPY
>> /* Starfire can do TCP/UDP checksumming */
>> diff --git a/drivers/net/ethernet/alacritech/slicoss.c b/drivers/net/ethernet/alacritech/slicoss.c
>> index 696517eae..544510f57 100644
>> --- a/drivers/net/ethernet/alacritech/slicoss.c
>> +++ b/drivers/net/ethernet/alacritech/slicoss.c
>> @@ -1749,7 +1749,7 @@ static int slic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
>> }
>>
>> pci_set_master(pdev);
>> - pci_try_set_mwi(pdev);
>> + pci_set_mwi(pdev);
>>
>> slic_configure_pci(pdev);
>>
>> diff --git a/drivers/net/ethernet/dec/tulip/tulip_core.c b/drivers/net/ethernet/dec/tulip/tulip_core.c
>> index c1dcd6ca1..4f6debb24 100644
>> --- a/drivers/net/ethernet/dec/tulip/tulip_core.c
>> +++ b/drivers/net/ethernet/dec/tulip/tulip_core.c
>> @@ -1193,10 +1193,7 @@ static void tulip_mwi_config(struct pci_dev *pdev, struct net_device *dev)
>> /* if we have any cache line size at all, we can do MRM and MWI */
>> csr0 |= MRM | MWI;
>>
>> - /* Enable MWI in the standard PCI command bit.
>> - * Check for the case where MWI is desired but not available
>> - */
>> - pci_try_set_mwi(pdev);
>> + pci_set_mwi(pdev);
>>
>> /* read result from hardware (in case bit refused to enable) */
>> pci_read_config_word(pdev, PCI_COMMAND, &pci_command);
>> diff --git a/drivers/net/ethernet/sun/cassini.c b/drivers/net/ethernet/sun/cassini.c
>> index 9ff894ba8..9a95ec989 100644
>> --- a/drivers/net/ethernet/sun/cassini.c
>> +++ b/drivers/net/ethernet/sun/cassini.c
>> @@ -4933,14 +4933,14 @@ static int cas_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
>> pci_cmd &= ~PCI_COMMAND_SERR;
>> pci_cmd |= PCI_COMMAND_PARITY;
>> pci_write_config_word(pdev, PCI_COMMAND, pci_cmd);
>> - if (pci_try_set_mwi(pdev))
>> + if (pci_set_mwi(pdev))
>> pr_warn("Could not enable MWI for %s\n", pci_name(pdev));
>>
>> cas_program_bridge(pdev);
>>
>> /*
>> * On some architectures, the default cache line size set
>> - * by pci_try_set_mwi reduces perforamnce. We have to increase
>> + * by pci_set_mwi reduces performance. We have to increase
>> * it for this case. To start, we'll print some configuration
>> * data.
>> */
>> diff --git a/drivers/net/wireless/intersil/p54/p54pci.c b/drivers/net/wireless/intersil/p54/p54pci.c
>> index e97ee547b..c76326d1e 100644
>> --- a/drivers/net/wireless/intersil/p54/p54pci.c
>> +++ b/drivers/net/wireless/intersil/p54/p54pci.c
>> @@ -583,7 +583,7 @@ static int p54p_probe(struct pci_dev *pdev,
>> }
>>
>> pci_set_master(pdev);
>> - pci_try_set_mwi(pdev);
>> + pci_set_mwi(pdev);
>>
>> pci_write_config_byte(pdev, 0x40, 0);
>> pci_write_config_byte(pdev, 0x41, 0);
>> diff --git a/drivers/net/wireless/intersil/prism54/islpci_hotplug.c b/drivers/net/wireless/intersil/prism54/islpci_hotplug.c
>> index 31a1e6132..e8087d9a5 100644
>> --- a/drivers/net/wireless/intersil/prism54/islpci_hotplug.c
>> +++ b/drivers/net/wireless/intersil/prism54/islpci_hotplug.c
>> @@ -153,8 +153,7 @@ prism54_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>> DEBUG(SHOW_TRACING, "%s: pci_set_master(pdev)\n", DRV_NAME);
>> pci_set_master(pdev);
>>
>> - /* enable MWI */
>> - pci_try_set_mwi(pdev);
>> + pci_set_mwi(pdev);
>>
>> /* setup the network device interface and its structure */
>> if (!(ndev = islpci_setup(pdev))) {
>> diff --git a/drivers/net/wireless/realtek/rtl818x/rtl8180/dev.c b/drivers/net/wireless/realtek/rtl818x/rtl8180/dev.c
>> index 2477e18c7..b259b0b58 100644
>> --- a/drivers/net/wireless/realtek/rtl818x/rtl8180/dev.c
>> +++ b/drivers/net/wireless/realtek/rtl818x/rtl8180/dev.c
>> @@ -1871,7 +1871,7 @@ static int rtl8180_probe(struct pci_dev *pdev,
>>
>> if (priv->chip_family != RTL818X_CHIP_FAMILY_RTL8180) {
>> priv->band.n_bitrates = ARRAY_SIZE(rtl818x_rates);
>> - pci_try_set_mwi(pdev);
>> + pci_set_mwi(pdev);
>> }
>>
>> if (priv->chip_family != RTL818X_CHIP_FAMILY_RTL8180)
>> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
>> index 9a5500287..f0ab432d2 100644
>> --- a/drivers/pci/pci.c
>> +++ b/drivers/pci/pci.c
>> @@ -4389,25 +4389,6 @@ int pcim_set_mwi(struct pci_dev *dev)
>> }
>> EXPORT_SYMBOL(pcim_set_mwi);
>>
>> -/**
>> - * 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)
>> -{
>> -#ifdef PCI_DISABLE_MWI
>> - return 0;
>> -#else
>> - return pci_set_mwi(dev);
>> -#endif
>> -}
>> -EXPORT_SYMBOL(pci_try_set_mwi);
>> -
>> /**
>> * pci_clear_mwi - disables Memory-Write-Invalidate for device dev
>> * @dev: the PCI device to disable
>> diff --git a/drivers/scsi/3w-9xxx.c b/drivers/scsi/3w-9xxx.c
>> index b4718a1b2..d869485e2 100644
>> --- a/drivers/scsi/3w-9xxx.c
>> +++ b/drivers/scsi/3w-9xxx.c
>> @@ -2018,7 +2018,7 @@ static int twa_probe(struct pci_dev *pdev, const struct pci_device_id *dev_id)
>> }
>>
>> pci_set_master(pdev);
>> - pci_try_set_mwi(pdev);
>> + pci_set_mwi(pdev);
>>
>> retval = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
>> if (retval)
>> @@ -2227,7 +2227,7 @@ static int __maybe_unused twa_resume(struct device *dev)
>>
>> printk(KERN_WARNING "3w-9xxx: Resuming host %d.\n", tw_dev->host->host_no);
>>
>> - pci_try_set_mwi(pdev);
>> + pci_set_mwi(pdev);
>>
>> retval = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
>> if (retval)
>> diff --git a/drivers/scsi/3w-sas.c b/drivers/scsi/3w-sas.c
>> index b8f1848ec..49ca153b8 100644
>> --- a/drivers/scsi/3w-sas.c
>> +++ b/drivers/scsi/3w-sas.c
>> @@ -1571,7 +1571,7 @@ static int twl_probe(struct pci_dev *pdev, const struct pci_device_id *dev_id)
>> }
>>
>> pci_set_master(pdev);
>> - pci_try_set_mwi(pdev);
>> + pci_set_mwi(pdev);
>>
>> retval = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
>> if (retval)
>> @@ -1790,7 +1790,7 @@ static int __maybe_unused twl_resume(struct device *dev)
>> TW_Device_Extension *tw_dev = (TW_Device_Extension *)host->hostdata;
>>
>> printk(KERN_WARNING "3w-sas: Resuming host %d.\n", tw_dev->host->host_no);
>> - pci_try_set_mwi(pdev);
>> + pci_set_mwi(pdev);
>>
>> retval = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
>> if (retval)
>> diff --git a/drivers/scsi/csiostor/csio_init.c b/drivers/scsi/csiostor/csio_init.c
>> index 390b07bf9..c20bf44c6 100644
>> --- a/drivers/scsi/csiostor/csio_init.c
>> +++ b/drivers/scsi/csiostor/csio_init.c
>> @@ -201,7 +201,7 @@ csio_pci_init(struct pci_dev *pdev, int *bars)
>> goto err_disable_device;
>>
>> pci_set_master(pdev);
>> - pci_try_set_mwi(pdev);
>> + pci_set_mwi(pdev);
>>
>> rv = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
>> if (rv)
>> diff --git a/drivers/scsi/lpfc/lpfc_init.c b/drivers/scsi/lpfc/lpfc_init.c
>> index ac67f420e..b4833c0f8 100644
>> --- a/drivers/scsi/lpfc/lpfc_init.c
>> +++ b/drivers/scsi/lpfc/lpfc_init.c
>> @@ -6119,7 +6119,7 @@ lpfc_enable_pci_dev(struct lpfc_hba *phba)
>> goto out_disable_device;
>> /* Set up device as PCI master and save state for EEH */
>> pci_set_master(pdev);
>> - pci_try_set_mwi(pdev);
>> + pci_set_mwi(pdev);
>> pci_save_state(pdev);
>>
>> /* PCIe EEH recovery on powerpc platforms needs fundamental reset */
>> diff --git a/drivers/scsi/qla2xxx/qla_init.c b/drivers/scsi/qla2xxx/qla_init.c
>> index 5626e9b69..76019dc2e 100644
>> --- a/drivers/scsi/qla2xxx/qla_init.c
>> +++ b/drivers/scsi/qla2xxx/qla_init.c
>> @@ -2356,7 +2356,7 @@ qla2100_pci_config(scsi_qla_host_t *vha)
>> struct device_reg_2xxx __iomem *reg = &ha->iobase->isp;
>>
>> pci_set_master(ha->pdev);
>> - pci_try_set_mwi(ha->pdev);
>> + pci_set_mwi(ha->pdev);
>>
>> pci_read_config_word(ha->pdev, PCI_COMMAND, &w);
>> w |= (PCI_COMMAND_PARITY | PCI_COMMAND_SERR);
>> @@ -2388,7 +2388,7 @@ qla2300_pci_config(scsi_qla_host_t *vha)
>> struct device_reg_2xxx __iomem *reg = &ha->iobase->isp;
>>
>> pci_set_master(ha->pdev);
>> - pci_try_set_mwi(ha->pdev);
>> + pci_set_mwi(ha->pdev);
>>
>> pci_read_config_word(ha->pdev, PCI_COMMAND, &w);
>> w |= (PCI_COMMAND_PARITY | PCI_COMMAND_SERR);
>> @@ -2469,7 +2469,7 @@ qla24xx_pci_config(scsi_qla_host_t *vha)
>> struct device_reg_24xx __iomem *reg = &ha->iobase->isp24;
>>
>> pci_set_master(ha->pdev);
>> - pci_try_set_mwi(ha->pdev);
>> + pci_set_mwi(ha->pdev);
>>
>> pci_read_config_word(ha->pdev, PCI_COMMAND, &w);
>> w |= (PCI_COMMAND_PARITY | PCI_COMMAND_SERR);
>> @@ -2511,7 +2511,7 @@ qla25xx_pci_config(scsi_qla_host_t *vha)
>> struct qla_hw_data *ha = vha->hw;
>>
>> pci_set_master(ha->pdev);
>> - pci_try_set_mwi(ha->pdev);
>> + pci_set_mwi(ha->pdev);
>>
>> pci_read_config_word(ha->pdev, PCI_COMMAND, &w);
>> w |= (PCI_COMMAND_PARITY | PCI_COMMAND_SERR);
>> diff --git a/drivers/scsi/qla2xxx/qla_mr.c b/drivers/scsi/qla2xxx/qla_mr.c
>> index ca7306685..e9763d8e3 100644
>> --- a/drivers/scsi/qla2xxx/qla_mr.c
>> +++ b/drivers/scsi/qla2xxx/qla_mr.c
>> @@ -499,7 +499,7 @@ qlafx00_pci_config(scsi_qla_host_t *vha)
>> struct qla_hw_data *ha = vha->hw;
>>
>> pci_set_master(ha->pdev);
>> - pci_try_set_mwi(ha->pdev);
>> + pci_set_mwi(ha->pdev);
>>
>> pci_read_config_word(ha->pdev, PCI_COMMAND, &w);
>> w |= (PCI_COMMAND_PARITY | PCI_COMMAND_SERR);
>> diff --git a/drivers/tty/serial/8250/8250_lpss.c b/drivers/tty/serial/8250/8250_lpss.c
>> index 4dee8a9e0..8acc1e5c9 100644
>> --- a/drivers/tty/serial/8250/8250_lpss.c
>> +++ b/drivers/tty/serial/8250/8250_lpss.c
>> @@ -193,7 +193,7 @@ static void qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port)
>> if (ret)
>> return;
>>
>> - pci_try_set_mwi(pdev);
>> + pci_set_mwi(pdev);
>>
>> /* Special DMA address for UART */
>> dma->rx_dma_addr = 0xfffff000;
>> diff --git a/drivers/usb/chipidea/ci_hdrc_pci.c b/drivers/usb/chipidea/ci_hdrc_pci.c
>> index d63479e1a..d412fa910 100644
>> --- a/drivers/usb/chipidea/ci_hdrc_pci.c
>> +++ b/drivers/usb/chipidea/ci_hdrc_pci.c
>> @@ -78,7 +78,7 @@ static int ci_hdrc_pci_probe(struct pci_dev *pdev,
>> }
>>
>> pci_set_master(pdev);
>> - pci_try_set_mwi(pdev);
>> + pci_set_mwi(pdev);
>>
>> /* register a nop PHY */
>> ci->phy = usb_phy_generic_register();
>> diff --git a/drivers/usb/gadget/udc/amd5536udc_pci.c b/drivers/usb/gadget/udc/amd5536udc_pci.c
>> index 8d387e0e4..9630ce8d3 100644
>> --- a/drivers/usb/gadget/udc/amd5536udc_pci.c
>> +++ b/drivers/usb/gadget/udc/amd5536udc_pci.c
>> @@ -151,7 +151,7 @@ static int udc_pci_probe(
>> dev->chiprev = pdev->revision;
>>
>> pci_set_master(pdev);
>> - pci_try_set_mwi(pdev);
>> + pci_set_mwi(pdev);
>>
>> /* init dma pools */
>> if (use_dma) {
>> diff --git a/drivers/usb/gadget/udc/net2280.c b/drivers/usb/gadget/udc/net2280.c
>> index fc9f99fe7..e15520698 100644
>> --- a/drivers/usb/gadget/udc/net2280.c
>> +++ b/drivers/usb/gadget/udc/net2280.c
>> @@ -3761,7 +3761,7 @@ static int net2280_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>> &dev->pci->pcimstctl);
>> /* erratum 0115 shouldn't appear: Linux inits PCI_LATENCY_TIMER */
>> pci_set_master(pdev);
>> - pci_try_set_mwi(pdev);
>> + pci_set_mwi(pdev);
>>
>> /* ... also flushes any posted pci writes */
>> dev->chiprev = get_idx_reg(dev->regs, REG_CHIPREV) & 0xffff;
>> diff --git a/drivers/usb/gadget/udc/pch_udc.c b/drivers/usb/gadget/udc/pch_udc.c
>> index a3c1fc924..4a0484a0c 100644
>> --- a/drivers/usb/gadget/udc/pch_udc.c
>> +++ b/drivers/usb/gadget/udc/pch_udc.c
>> @@ -3100,7 +3100,7 @@ static int pch_udc_probe(struct pci_dev *pdev,
>> }
>>
>> pci_set_master(pdev);
>> - pci_try_set_mwi(pdev);
>> + pci_set_mwi(pdev);
>>
>> /* device struct setup */
>> spin_lock_init(&dev->lock);
>> diff --git a/include/linux/pci.h b/include/linux/pci.h
>> index de75f6a4d..c590f616d 100644
>> --- a/include/linux/pci.h
>> +++ b/include/linux/pci.h
>> @@ -1191,9 +1191,8 @@ void pci_clear_master(struct pci_dev *dev);
>>
>> int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state);
>> int pci_set_cacheline_size(struct pci_dev *dev);
>> -int __must_check pci_set_mwi(struct pci_dev *dev);
>> -int __must_check pcim_set_mwi(struct pci_dev *dev);
>> -int pci_try_set_mwi(struct pci_dev *dev);
>> +int pci_set_mwi(struct pci_dev *dev);
>> +int pcim_set_mwi(struct pci_dev *dev);
>> void pci_clear_mwi(struct pci_dev *dev);
>> void pci_intx(struct pci_dev *dev, int enable);
>> bool pci_check_and_mask_intx(struct pci_dev *dev);
>> --
>> 2.29.2
>>