> -----Original Message----- > From: Richard Zhu > Sent: Tuesday, October 19, 2021 3:40 PM > To: Lucas Stach <l.stach@xxxxxxxxxxxxxx>; bhelgaas@xxxxxxxxxx; > lorenzo.pieralisi@xxxxxxx > Cc: linux-pci@xxxxxxxxxxxxxxx; dl-linux-imx <linux-imx@xxxxxxx>; > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > kernel@xxxxxxxxxxxxxx > Subject: RE: [RESEND v2 3/5] PCI: imx6: Fix the regulator dump when link > never came up > > > -----Original Message----- > > From: Lucas Stach <l.stach@xxxxxxxxxxxxxx> > > Sent: Saturday, October 16, 2021 2:23 AM > > To: Richard Zhu <hongxing.zhu@xxxxxxx>; bhelgaas@xxxxxxxxxx; > > lorenzo.pieralisi@xxxxxxx > > Cc: linux-pci@xxxxxxxxxxxxxxx; dl-linux-imx <linux-imx@xxxxxxx>; > > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > > kernel@xxxxxxxxxxxxxx > > Subject: Re: [RESEND v2 3/5] PCI: imx6: Fix the regulator dump when > > link never came up > > > > Am Freitag, dem 15.10.2021 um 14:05 +0800 schrieb Richard Zhu: > > > When PCIe PHY link never came up and vpcie regulator is present, > > > there would be following dump when try to put the regulator. > > > Disable this regulator to fix this dump when link never came up. > > > > > > imx6q-pcie 33800000.pcie: Phy link never came up > > > imx6q-pcie: probe of 33800000.pcie failed with error -110 > > > ------------[ cut here ]------------ > > > WARNING: CPU: 3 PID: 119 at drivers/regulator/core.c:2256 > > _regulator_put.part.0+0x14c/0x158 > > > Modules linked in: > > > CPU: 3 PID: 119 Comm: kworker/u8:2 Not tainted > > 5.13.0-rc7-next-20210625-94710-ge4e92b2588a3 #10 > > > Hardware name: FSL i.MX8MM EVK board (DT) > > > Workqueue: events_unbound async_run_entry_fn > > > pstate: 80000005 (Nzcv daif -PAN -UAO -TCO BTYPE=--) > > > pc : _regulator_put.part.0+0x14c/0x158 > > > lr : regulator_put+0x34/0x48 > > > sp : ffff8000122ebb30 > > > x29: ffff8000122ebb30 x28: ffff800011be7000 x27: > 0000000000000000 > > > x26: 0000000000000000 x25: 0000000000000000 x24: > ffff00000025f2bc > > > x23: ffff00000025f2c0 x22: ffff00000025f010 x21: ffff8000122ebc18 > > > x20: ffff800011e3fa60 x19: ffff00000375fd80 x18: 0000000000000010 > > > x17: 000000040044ffff x16: 00400032b5503510 x15: > > 0000000000000108 > > > x14: ffff0000003cc938 x13: 00000000ffffffea x12: 0000000000000000 > > > x11: 0000000000000000 x10: ffff80001076ba88 x9 : ffff80001076a540 > > > x8 : ffff00000025f2c0 x7 : ffff0000001f4450 x6 : ffff000000176cd8 > > > x5 : ffff000003857880 x4 : 0000000000000000 x3 : ffff800011e3fe30 > > > x2 : ffff0000003cc4c0 x1 : 0000000000000000 x0 : 0000000000000001 > > > Call trace: > > > _regulator_put.part.0+0x14c/0x158 > > > regulator_put+0x34/0x48 > > > devm_regulator_release+0x10/0x18 > > > release_nodes+0x38/0x60 > > > devres_release_all+0x88/0xd0 > > > really_probe+0xd0/0x2e8 > > > __driver_probe_device+0x74/0xd8 > > > driver_probe_device+0x7c/0x108 > > > __device_attach_driver+0x8c/0xd0 > > > bus_for_each_drv+0x74/0xc0 > > > __device_attach_async_helper+0xb4/0xd8 > > > async_run_entry_fn+0x30/0x100 > > > process_one_work+0x19c/0x320 > > > worker_thread+0x48/0x418 > > > kthread+0x14c/0x158 > > > ret_from_fork+0x10/0x18 > > > ---[ end trace 3664ca4a50ce849b ]--- > > > > > > Signed-off-by: Richard Zhu <hongxing.zhu@xxxxxxx> > > > --- > > > drivers/pci/controller/dwc/pci-imx6.c | 2 ++ > > > 1 file changed, 2 insertions(+) > > > > > > diff --git a/drivers/pci/controller/dwc/pci-imx6.c > > > b/drivers/pci/controller/dwc/pci-imx6.c > > > index 3372775834a2..cc837f8bf6d4 100644 > > > --- a/drivers/pci/controller/dwc/pci-imx6.c > > > +++ b/drivers/pci/controller/dwc/pci-imx6.c > > > @@ -853,6 +853,8 @@ static int imx6_pcie_start_link(struct dw_pcie > *pci) > > > dw_pcie_readl_dbi(pci, PCIE_PORT_DEBUG0), > > > dw_pcie_readl_dbi(pci, PCIE_PORT_DEBUG1)); > > > imx6_pcie_reset_phy(imx6_pcie); > > > + if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > > 0) > > > + regulator_disable(imx6_pcie->vpcie); > > > > This doesn't seem like the right place to add this. I guess it would > > be better to have proper error handling after dw_pcie_host_init to > > roll back things like the clock and regulator enable. > [Richard Zhu] This is good suggestion. It's make sense that move the regulator > disable to the dw_pcie_host_init error handling since the regulator have the > enabled check, before to disable it. > But it seems that there are some potential problems when do the similar > operations to the clocks disable here. > Because that the dw_pcie_host_init might have some error returns when the > host_init is not invoked at all. > How to handle this situation although this is one corner case? > [Richard Zhu] I have an idea to handle this case. Add one more callback(e.x: host_exit() ) into dw_pcie_host_ops struct, then do the host_exit() when there is a error return after host_init() is invoked. How about this solution? I would send the v3 patch-set later if you don't say no to this method. BR Richard > Best Regards > Richard Zhu > > > > Regards, > > Lucas > > > > > return ret; > > > } > > > > >
