> -----Original Message----- > From: Baruch Siach [mailto:baruch@xxxxxxxxxx] > Sent: 2018年12月13日 14:37 > To: Richard Zhu <hongxing.zhu@xxxxxxx> > Cc: bhelgaas@xxxxxxxxxx; lorenzo.pieralisi@xxxxxxx; > l.stach@xxxxxxxxxxxxxx; andrew.smirnov@xxxxxxxxx; > linux-pci@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > Subject: Re: [PATCH] PCI: imx: make msi work without pcieportbus > > Hi Richard, > > Thanks for debugging this issue. One question below. > > Richard Zhu writes: > > MSI_EN of iMX PCIe RC would be asserted when PCIEPORTBUS driver is > > selected. > > Thus, the MSI works fine on iMX PCIe before. > > Make a double check on this bit, and assert it when it is not set and > > MSI is supported. > > Otherwise, the MSI wouldn't be triggered although the EP is present > > and the MSIs are assigned. > > > > Signed-off-by: Richard Zhu <hongxing.zhu@xxxxxxx> > > --- > > drivers/pci/controller/dwc/pci-imx6.c | 10 ++++++++++ > > 1 file changed, 10 insertions(+) > > > > diff --git a/drivers/pci/controller/dwc/pci-imx6.c > > b/drivers/pci/controller/dwc/pci-imx6.c > > index 26087b3..6c3e56b 100644 > > --- a/drivers/pci/controller/dwc/pci-imx6.c > > +++ b/drivers/pci/controller/dwc/pci-imx6.c > > @@ -74,6 +74,7 @@ struct imx6_pcie { > > #define PHY_PLL_LOCK_WAIT_USLEEP_MAX 200 > > > > /* PCIe Root Complex registers (memory-mapped) */ > > +#define PCI_MSI_CAP 0x50 > > #define PCIE_RC_LCR 0x7c > > #define PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN1 0x1 > > #define PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN2 0x2 > > @@ -926,6 +927,7 @@ static int imx6_pcie_probe(struct platform_device > *pdev) > > struct resource *dbi_base; > > struct device_node *node = dev->of_node; > > int ret; > > + u16 val; > > > > imx6_pcie = devm_kzalloc(dev, sizeof(*imx6_pcie), GFP_KERNEL); > > if (!imx6_pcie) > > @@ -1070,6 +1072,14 @@ static int imx6_pcie_probe(struct > platform_device *pdev) > > ret = imx6_add_pcie_port(imx6_pcie, pdev); > > if (ret < 0) > > return ret; > > + if (IS_ENABLED(CONFIG_PCI_MSI)) { > > + val = dw_pcie_readw_dbi(pci, PCI_MSI_CAP + PCI_MSI_FLAGS); > > + if ((val & PCI_MSI_FLAGS_ENABLE) == 0) { > > + val |= PCI_MSI_FLAGS_ENABLE; > > Why not assert the PCI_MSI_FLAGS_ENABLE flag unconditionally here? [Richard Zhu] Thanks for your kindly review. It's more efficient to set it unconditionally. I would change it in next version. > > > + dw_pcie_writew_dbi(pci, PCI_MSI_CAP + > > + PCI_MSI_FLAGS, val); > > + } > > + } > > > > return 0; > > } > > baruch > > -- > > https://emea01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fbaru > ch.siach.name%2Fblog%2F&data=02%7C01%7Chongxing.zhu%40nxp.co > m%7Ce9d8a943e90f4055f41708d660c55801%7C686ea1d3bc2b4c6fa92cd99 > c5c301635%7C0%7C0%7C636802798043957806&sdata=hh4ichdPcGA0 > N1om4AdZIOaEX3HE2rpW6jYl8m1F%2FWE%3D&reserved=0 > ~. .~ Tk Open Systems > =}------------------------------------------------ooO--U--Ooo------------{= > - baruch@xxxxxxxxxx - tel: +972.52.368.4656, > https://emea01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww > .tkos.co.il&data=02%7C01%7Chongxing.zhu%40nxp.com%7Ce9d8a943e > 90f4055f41708d660c55801%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0 > %7C0%7C636802798043957806&sdata=awQAaFvN9%2B63IxOonaox7O > JxZoTtSHJGFNKSXEKPKso%3D&reserved=0 -
