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Date:   Sun, 28 Mar 2021 21:49:25 +0800
From:   Dejin Zheng <zhengdejin5@gmail.com>
To:     dann frazier <dann.frazier@canonical.com>
Cc:     tjoseph@cadence.com, lorenzo.pieralisi@arm.com, robh@kernel.org,
        bhelgaas@google.com, thierry.reding@gmail.com,
        toan@os.amperecomputing.com, ley.foon.tan@intel.com,
        shawn.lin@rock-chips.com, linux-pci@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] PCI: controller: convert to
 devm_platform_ioremap_resource_byname()
Message-ID: <20210328134925.GA247508@nuc8i5>
References: <20200602171601.17630-1-zhengdejin5@gmail.com>
 <YF9zQscGC7T/ZsN+@xps13.dannf>
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In-Reply-To: <YF9zQscGC7T/ZsN+@xps13.dannf>
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On Sat, Mar 27, 2021 at 12:02:42PM -0600, dann frazier wrote:
Hi Dann,

I'm so sorry for that, And there is a mistake with my patch that caused
this problem. Thank you very much for telling me this, I will fix it as
soon as possible.

> On Wed, Jun 03, 2020 at 01:16:01AM +0800, Dejin Zheng wrote:
> > Use devm_platform_ioremap_resource_byname() to simplify codes.
> > it contains platform_get_resource_byname() and devm_ioremap_resource().
> > 
> > Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>
> > ---
> > v1 -> v2:
> > 	- Discard changes to the file drivers/pci/controller/pcie-xilinx-nwl.c
> > 	  Due to my mistakes, my patch will modify pcie-xilinx-nwl.c,
> > 	  but it still need to use the res variable, but
> > 	  devm_platform_ioremap_resource_byname() funtion can't assign a
> > 	  value to the variable res. kbuild test robot report it. Thanks
> > 	  very much for kbuild test robot <lkp@intel.com>.
> > 
> >  drivers/pci/controller/cadence/pcie-cadence-ep.c   | 3 +--
> >  drivers/pci/controller/cadence/pcie-cadence-host.c | 3 +--
> >  drivers/pci/controller/pci-tegra.c                 | 8 +++-----
> >  drivers/pci/controller/pci-xgene.c                 | 3 +--
> >  drivers/pci/controller/pcie-altera-msi.c           | 3 +--
> >  drivers/pci/controller/pcie-altera.c               | 9 +++------
> >  drivers/pci/controller/pcie-mediatek.c             | 4 +---
> >  drivers/pci/controller/pcie-rockchip.c             | 5 ++---
> >  8 files changed, 13 insertions(+), 25 deletions(-)
> > 
> 
> hey,
>   I found that recent kernels fail to initialize PCI devices on our HP
> m400 Moonshot cartridges, which are based on the X-Gene SoC. I
> bisected the issue down to this commit. I found that just reverting
> this hunk in pci-xgene.c is enough to get v5.12 rcs booting again:
> 
> > diff --git a/drivers/pci/controller/pci-xgene.c b/drivers/pci/controller/pci-xgene.c
> > index d1efa8ffbae1..1431a18eb02c 100644
> > --- a/drivers/pci/controller/pci-xgene.c
> > +++ b/drivers/pci/controller/pci-xgene.c
> > @@ -355,8 +355,7 @@ static int xgene_pcie_map_reg(struct xgene_pcie_port *port,
> >  	if (IS_ERR(port->csr_base))
> >  		return PTR_ERR(port->csr_base);
> >  
> > -	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cfg");
> > -	port->cfg_base = devm_ioremap_resource(dev, res);
> > +	port->cfg_base = devm_platform_ioremap_resource_byname(pdev, "cfg");
> >  	if (IS_ERR(port->cfg_base))
> >  		return PTR_ERR(port->cfg_base);
> >  	port->cfg_addr = res->start;
The mistake of this patch is here, port->cfg_addr need the res->start,
But this patch remove the res of get "cfg" resource. here use the wrong
data by get "csr" resource in the previous.

BR,
Dejin
> 
> 
> In case it helps, here's the PCI initialization portion of dmesg when
> it fails:
> 
> [    0.756359] xgene-pcie 1f500000.pcie: host bridge /soc/pcie@1f500000 ranges:
> [    0.756372] xgene-pcie 1f500000.pcie:   No bus range found for /soc/pcie@1f500000, using [bus 00-ff]
> [    0.756387] xgene-pcie 1f500000.pcie:      MEM 0xa130000000..0xa1afffffff -> 0x0030000000
> [    0.756404] xgene-pcie 1f500000.pcie:   IB MEM 0x4000000000..0x7fffffffff -> 0x4000000000
> [    0.756459] xgene-pcie 1f500000.pcie: (rc) x8 gen-2 link up
> [    0.756525] xgene-pcie 1f500000.pcie: PCI host bridge to bus 0000:00
> [    0.756532] pci_bus 0000:00: root bus resource [bus 00-ff]
> [    0.756538] pci_bus 0000:00: root bus resource [mem 0xa130000000-0xa1afffffff] (bus address [0x30000000-0xafffffff])
> 
> 
> and here's what it looks like when it works:
> 
> [    0.756793] xgene-pcie 1f500000.pcie: host bridge /soc/pcie@1f500000 ranges:
> [    0.756807] xgene-pcie 1f500000.pcie:   No bus range found for /soc/pcie@1f500000, using [bus 00-ff]
> [    0.756822] xgene-pcie 1f500000.pcie:      MEM 0xa130000000..0xa1afffffff -> 0x0030000000
> [    0.756838] xgene-pcie 1f500000.pcie:   IB MEM 0x4000000000..0x7fffffffff -> 0x4000000000
> [    0.756892] xgene-pcie 1f500000.pcie: (rc) x8 gen-2 link up
> [    0.756962] xgene-pcie 1f500000.pcie: PCI host bridge to bus 0000:00
> [    0.756968] pci_bus 0000:00: root bus resource [bus 00-ff]
> [    0.756974] pci_bus 0000:00: root bus resource [mem 0xa130000000-0xa1afffffff] (bus address [0x30000000-0xafffffff])
> [    0.757006] pci 0000:00:00.0: [10e8:e004] type 01 class 0x060400
> [    0.757014] pci_bus 0000:00: 2-byte config write to 0000:00:00.0 offset 0x4 may corrupt adjacent RW1C bits
> [    0.757022] pci_bus 0000:00: 2-byte config write to 0000:00:00.0 offset 0x4 may corrupt adjacent RW1C bits
> [    0.757032] pci_bus 0000:00: 2-byte config write to 0000:00:00.0 offset 0x4 may corrupt adjacent RW1C bits
> [    0.757039] pci_bus 0000:00: 2-byte config write to 0000:00:00.0 offset 0x4 may corrupt adjacent RW1C bits
> [    0.757046] pci_bus 0000:00: 2-byte config write to 0000:00:00.0 offset 0x4 may corrupt adjacent RW1C bits
> [    0.757052] pci_bus 0000:00: 2-byte config write to 0000:00:00.0 offset 0x4 may corrupt adjacent RW1C bits
> [    0.757059] pci_bus 0000:00: 2-byte config write to 0000:00:00.0 offset 0x4 may corrupt adjacent RW1C bits
> [    0.757068] pci_bus 0000:00: 2-byte config write to 0000:00:00.0 offset 0x4 may corrupt adjacent RW1C bits
> [    0.757094] pci_bus 0000:00: 2-byte config write to 0000:00:00.0 offset 0x3e may corrupt adjacent RW1C bits
> [    0.757143] pci 0000:00:00.0: supports D1 D2
> [    0.757589] pci_bus 0000:00: 2-byte config write to 0000:00:00.0 offset 0x3e may corrupt adjacent RW1C bits
> [    0.757968] pci 0000:01:00.0: [15b3:1007] type 00 class 0x020000
> [    0.758381] pci 0000:01:00.0: reg 0x10: [mem 0x00100000-0x001fffff 64bit]
> [    0.758642] pci 0000:01:00.0: reg 0x18: [mem 0x00800000-0x00ffffff 64bit pref]
> [    0.761110] pci 0000:01:00.0: reg 0x134: [mem 0x00000000-0x007fffff 64bit pref]
> [    0.761115] pci 0000:01:00.0: VF(n) BAR2 space: [mem 0x00000000-0x03ffffff 64bit pref] (contains BAR2 for 8 VFs)
> [    0.762921] pci 0000:01:00.0: 32.000 Gb/s available PCIe bandwidth, limited by 5.0 GT/s PCIe x8 link at 0000:00:00.0 (capable of 63.008 Gb/s with 8.0 GT/s PCIe x8 link)
> [    0.773939] pci 0000:00:00.0: BAR 15: assigned [mem 0xa130000000-0xa1347fffff 64bit pref]
> [    0.773947] pci 0000:00:00.0: BAR 14: assigned [mem 0xa134800000-0xa1348fffff]
> [    0.773954] pci 0000:01:00.0: BAR 2: assigned [mem 0xa130000000-0xa1307fffff 64bit pref]
> [    0.774136] pci 0000:01:00.0: BAR 9: assigned [mem 0xa130800000-0xa1347fffff 64bit pref]
> [    0.774203] pci 0000:01:00.0: BAR 0: assigned [mem 0xa134800000-0xa1348fffff 64bit]
> [    0.774384] pci 0000:00:00.0: PCI bridge to [bus 01]
> [    0.774391] pci 0000:00:00.0:   bridge window [mem 0xa134800000-0xa1348fffff]
> [    0.774397] pci 0000:00:00.0:   bridge window [mem 0xa130000000-0xa1347fffff 64bit pref]
> [    0.774576] pcieport 0000:00:00.0: PME: Signaling with IRQ 89
> [    0.774734] pcieport 0000:00:00.0: AER: enabled with IRQ 89
> 
> 
>   -dann