On Tue, 21 Jun 2022 at 22:32, Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote: > > On Tue, Jun 21, 2022 at 01:23:30PM +0200, Robert Marko wrote: > > IPQ8074 has one Gen2 and one Gen3 port, currently the Gen2 port will > > cause the system to hang as its using DBI registers in the .init > > and those are only accesible after phy_power_on(). > > Is the fact that IPQ8074 has both a Gen2 and a Gen3 port relevant to > this patch? I don't see the connection. Hi Bjorn, Not really, I can remove it from the description as this only affects the Gen2 port, Gen3 support is dependant on the IPQ6018 support getting merged as it uses the same controller. > > I see that qcom_pcie_host_init() does: > > qcom_pcie_host_init > pcie->cfg->ops->init(pcie) > phy_power_on(pcie->phy) > pcie->cfg->ops->post_init(pcie) > > and that you're moving DBI register accesses from > qcom_pcie_init_2_3_3() to qcom_pcie_post_init_2_3_3(). > > But I also see DBI register accesses in other .init() functions: > > qcom_pcie_init_2_1_0 > qcom_pcie_init_1_0_0 (oddly out of order) > qcom_pcie_init_2_3_2 > qcom_pcie_init_2_4_0 > > Why do these accesses not need to be moved? I assume it's because > pcie->phy is an optional PHY and phy_power_on() does nothing on those > controllers? As far as I could figure out from QCA-s 5.4 kernel, various commits, and QCA-s attempts to solve this already upstream the Gen2 controller in IPQ8074 is a bit special and requires the PHY to be powered on before DBI could be accessed or else the board will hang as it does for me. I can only assume that this is an IPQ8074-specific quirk and other IP-s are not affected like this, so they were not broken. > > Whatever the reason, I think the DBI accesses should be done > consistently in .post_init(). I see that Dmitry's previous patches > removed all those .post_init() functions, but I think the consistency > is worth having. > > Perhaps we could reorder the patches so this patch comes first, moves > the DBI accesses into .post_init(), then Dmitry's patches could be > rebased on top to drop the clock handling? > > > So solve this by splitting the DBI read/writes to .post_init. I am open to anything to get this fixed properly, you are gonna need to point me in the right direction as I am really new to PCI. Regards, Robert > > > > Fixes: a0fd361db8e5 ("PCI: dwc: Move "dbi", "dbi2", and "addr_space" resource setup into common code") > > Signed-off-by: Robert Marko <robimarko@xxxxxxxxx> > > --- > > Changes in v2: > > * Rebase onto next-20220621 > > --- > > drivers/pci/controller/dwc/pcie-qcom.c | 48 +++++++++++++++----------- > > 1 file changed, 28 insertions(+), 20 deletions(-) > > > > diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c > > index 51fed83484af..da6d79d61397 100644 > > --- a/drivers/pci/controller/dwc/pcie-qcom.c > > +++ b/drivers/pci/controller/dwc/pcie-qcom.c > > @@ -1061,9 +1061,7 @@ static int qcom_pcie_init_2_3_3(struct qcom_pcie *pcie) > > struct qcom_pcie_resources_2_3_3 *res = &pcie->res.v2_3_3; > > struct dw_pcie *pci = pcie->pci; > > struct device *dev = pci->dev; > > - u16 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); > > int i, ret; > > - u32 val; > > > > for (i = 0; i < ARRAY_SIZE(res->rst); i++) { > > ret = reset_control_assert(res->rst[i]); > > @@ -1120,6 +1118,33 @@ static int qcom_pcie_init_2_3_3(struct qcom_pcie *pcie) > > goto err_clk_aux; > > } > > > > + return 0; > > + > > +err_clk_aux: > > + clk_disable_unprepare(res->ahb_clk); > > +err_clk_ahb: > > + clk_disable_unprepare(res->axi_s_clk); > > +err_clk_axi_s: > > + clk_disable_unprepare(res->axi_m_clk); > > +err_clk_axi_m: > > + clk_disable_unprepare(res->iface); > > +err_clk_iface: > > + /* > > + * Not checking for failure, will anyway return > > + * the original failure in 'ret'. > > + */ > > + for (i = 0; i < ARRAY_SIZE(res->rst); i++) > > + reset_control_assert(res->rst[i]); > > + > > + return ret; > > +} > > + > > +static int qcom_pcie_post_init_2_3_3(struct qcom_pcie *pcie) > > +{ > > + struct dw_pcie *pci = pcie->pci; > > + u16 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); > > + u32 val; > > + > > writel(SLV_ADDR_SPACE_SZ, > > pcie->parf + PCIE20_v3_PARF_SLV_ADDR_SPACE_SIZE); > > > > @@ -1147,24 +1172,6 @@ static int qcom_pcie_init_2_3_3(struct qcom_pcie *pcie) > > PCI_EXP_DEVCTL2); > > > > return 0; > > - > > -err_clk_aux: > > - clk_disable_unprepare(res->ahb_clk); > > -err_clk_ahb: > > - clk_disable_unprepare(res->axi_s_clk); > > -err_clk_axi_s: > > - clk_disable_unprepare(res->axi_m_clk); > > -err_clk_axi_m: > > - clk_disable_unprepare(res->iface); > > -err_clk_iface: > > - /* > > - * Not checking for failure, will anyway return > > - * the original failure in 'ret'. > > - */ > > - for (i = 0; i < ARRAY_SIZE(res->rst); i++) > > - reset_control_assert(res->rst[i]); > > - > > - return ret; > > } > > > > static int qcom_pcie_get_resources_2_7_0(struct qcom_pcie *pcie) > > @@ -1598,6 +1605,7 @@ static const struct qcom_pcie_ops ops_2_4_0 = { > > static const struct qcom_pcie_ops ops_2_3_3 = { > > .get_resources = qcom_pcie_get_resources_2_3_3, > > .init = qcom_pcie_init_2_3_3, > > + .post_init = qcom_pcie_post_init_2_3_3, > > .deinit = qcom_pcie_deinit_2_3_3, > > .ltssm_enable = qcom_pcie_2_3_2_ltssm_enable, > > }; > > -- > > 2.36.1 > >