| Message ID | 20220528224423.7017-2-jim2101024@gmail.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | PCI: brcmstb: Fix regression regarding missing PCIe linkup | expand |
Hi Jim, Jim Quinlan <jim2101024@gmail.com> (2022-05-28): > commit 93e41f3fca3d ("PCI: brcmstb: Add control of subdevice voltage regulators") > > introduced a regression on the PCIe RPi4 Compute Module. If the PCIe > root port DT node described in [2] was missing, no linkup would be attempted, > and subsequent accesses would cause a panic because this particular PCIe HW > causes a CPU abort on illegal accesses (instead of returning 0xffffffff). > > We fix this by allowing the DT root port node to be missing, as it behaved > before the original patchset messed things up. > > In addition, two small changes are made: > > 1. Having pci_subdev_regulators_remove_bus() call > regulator_bulk_free() in addtion to regulator_bulk_disable(). > 2. Having brcm_pcie_add_bus() return 0 if there is an > error in calling pci_subdev_regulators_add_bus(). > Instead, we dev_err() and turn on our refusal mode instead. > > It would be best if this commit were tested by someone with a Rpi CM4 > platform, as that is how the regression was found. I have only emulated > the problem and fix on different platform. Testing is less flawless than it was with the earlier version, but this might be related to the fact master has moved a lot since then (from v5.18-rcX to open merge window). Overall, it's still a net win over the status quo (broken boot). Applying your patch on 664a393a2663a0f62fc1b18157ccae33dcdbb8c8 and performing cold boots is mostly fine: - without anything on the PCIe slot; - with a PCIe→quad-USB extension board, a USB keyboard and a USB stick (both work fine). However, with an empty PCIe slot, I'm no longer able to perform the following (which was rock solid, and has been used in all my testing up to now): - boot the exact same Debian stable image as before (running v5.10.y if that matters); - deploy the patched kernel; - enable serial console; - reboot into the patched kernel. PCI-related messages, a call trace, and broken storage: [ 3.425331] brcm-pcie fd500000.pcie: host bridge /scb/pcie@7d500000 ranges: [ 3.425353] brcm-pcie fd500000.pcie: No bus range found for /scb/pcie@7d500000, using [bus 00-ff] [ 3.425388] brcm-pcie fd500000.pcie: MEM 0x0600000000..0x0603ffffff -> 0x00f8000000 [ 3.425420] brcm-pcie fd500000.pcie: IB MEM 0x0000000000..0x003fffffff -> 0x0400000000 [ 3.426229] brcm-pcie fd500000.pcie: PCI host bridge to bus 0000:00 [ 3.426243] pci_bus 0000:00: root bus resource [bus 00-ff] [ 3.426255] pci_bus 0000:00: root bus resource [mem 0x600000000-0x603ffffff] (bus address [0xf8000000-0xfbffffff]) [ 3.426303] pci 0000:00:00.0: [14e4:2711] type 01 class 0x060400 [ 3.426398] pci 0000:00:00.0: PME# supported from D0 D3hot [ 3.428797] pci 0000:00:00.0: bridge configuration invalid ([bus 00-00]), reconfiguring [ 3.745909] brcm-pcie fd500000.pcie: link down [ 3.747915] pci_bus 0000:01: busn_res: [bus 01-ff] end is updated to 01 [ 3.747944] pci 0000:00:00.0: PCI bridge to [bus 01] [ 3.748294] pcieport 0000:00:00.0: PME: Signaling with IRQ 23 [ 3.748691] pcieport 0000:00:00.0: AER: enabled with IRQ 23 [ 3.749201] pci_bus 0000:01: busn_res: [bus 01] is released [ 3.749462] pci_bus 0000:00: busn_res: [bus 00-ff] is released … [ 5.617308] irq 35: nobody cared (try booting with the "irqpoll" option) [ 5.617335] CPU: 0 PID: 127 Comm: systemd-udevd Not tainted 5.18.0+ #1 [ 5.617350] Hardware name: Raspberry Pi Compute Module 4 Rev 1.0 (DT) [ 5.617358] Call trace: [ 5.617362] dump_backtrace+0xc0/0x130 [ 5.617386] show_stack+0x24/0x70 [ 5.617396] dump_stack_lvl+0x68/0x84 [ 5.617415] dump_stack+0x18/0x34 [ 5.617426] __report_bad_irq+0x54/0x16c [ 5.617436] note_interrupt+0x324/0x41c [ 5.617445] handle_irq_event+0xc0/0x180 [ 5.617460] handle_fasteoi_irq+0xc8/0x1fc [ 5.617468] generic_handle_domain_irq+0x38/0x50 [ 5.617481] gic_handle_irq+0x68/0xa0 [ 5.617489] call_on_irq_stack+0x2c/0x60 [ 5.617500] do_interrupt_handler+0x88/0x90 [ 5.617511] el0_interrupt+0x58/0x124 [ 5.617526] __el0_irq_handler_common+0x18/0x2c [ 5.617538] el0t_64_irq_handler+0x10/0x20 [ 5.617549] el0t_64_irq+0x18c/0x190 [ 5.617558] handlers: [ 5.617563] [<(____ptrval____)>] sdhci_irq [sdhci] threaded [<(____ptrval____)>] sdhci_thread_irq [sdhci] [ 5.617613] Disabling IRQ #35 … [ 15.581894] mmc0: Timeout waiting for hardware cmd interrupt. [ 15.581914] mmc0: sdhci: ============ SDHCI REGISTER DUMP =========== [ 15.581920] mmc0: sdhci: Sys addr: 0x00000000 | Version: 0x00001002 [ 15.581931] mmc0: sdhci: Blk size: 0x00000000 | Blk cnt: 0x00000000 [ 15.581937] mmc0: sdhci: Argument: 0x00000c00 | Trn mode: 0x00000000 [ 15.581944] mmc0: sdhci: Present: 0x1fff0000 | Host ctl: 0x00000001 [ 15.581951] mmc0: sdhci: Power: 0x0000000f | Blk gap: 0x00000080 [ 15.581957] mmc0: sdhci: Wake-up: 0x00000000 | Clock: 0x00007d07 [ 15.581964] mmc0: sdhci: Timeout: 0x00000000 | Int stat: 0x00018000 [ 15.581971] mmc0: sdhci: Int enab: 0x00ff1003 | Sig enab: 0x00ff1003 [ 15.581976] mmc0: sdhci: ACmd stat: 0x00000000 | Slot int: 0x00000001 [ 15.581982] mmc0: sdhci: Caps: 0x45ee6432 | Caps_1: 0x0000a525 [ 15.581988] mmc0: sdhci: Cmd: 0x0000341a | Max curr: 0x00080008 [ 15.581996] mmc0: sdhci: Resp[0]: 0x00000000 | Resp[1]: 0x00000000 [ 15.582001] mmc0: sdhci: Resp[2]: 0x00000000 | Resp[3]: 0x00000000 [ 15.582005] mmc0: sdhci: Host ctl2: 0x00000000 [ 15.582011] mmc0: sdhci: ADMA Err: 0x00000000 | ADMA Ptr: 0x00000000 [ 15.582016] mmc0: sdhci: ============================================ This last part gets repeated over and over, and storage (external SD card) never comes up. I can share fuller logs if that's desirable. I can also test booting with irqpoll if that's desirable. Or anything else that might help. I did check that applying the same patch on top of the v5.18 tag gives good results (cold boots and reboots are fine, with or without an empty PCIe slot, as that was the case during earlier test sessions), so I'd guess something changed since then, and makes reboots more brittle than they used to be. I can also check applying the v1 patch on top of master and compare results, to give a different perspective. But I'd also be happy to get some directions as to which test(s) would be most beneficial, which would help me cut down on combinatorics. Cheers,
On Sat, May 28, 2022 at 9:15 PM Cyril Brulebois <kibi@debian.org> wrote: > > Hi Jim, > > Jim Quinlan <jim2101024@gmail.com> (2022-05-28): > > commit 93e41f3fca3d ("PCI: brcmstb: Add control of subdevice voltage regulators")vpcie3v3-supply > > > > introduced a regression on the PCIe RPi4 Compute Module. If the PCIe > > root port DT node described in [2] was missing, no linkup would be attempted, > > and subsequent accesses would cause a panic because this particular PCIe HW > > causes a CPU abort on illegal accesses (instead of returning 0xffffffff). > > > > We fix this by allowing the DT root port node to be missing, as it behaved > > before the original patchset messed things up. > > > > In addition, two small changes are made: > > > > 1. Having pci_subdev_regulators_remove_bus() call > > regulator_bulk_free() in addtion to regulator_bulk_disable(). > > 2. Having brcm_pcie_add_bus() return 0 if there is an > > error in calling pci_subdev_regulators_add_bus(). > > Instead, we dev_err() and turn on our refusal mode instead. > > > > It would be best if this commit were tested by someone with a Rpi CM4 > > platform, as that is how the regression was found. I have only emulated > > the problem and fix on different platform. > > Testing is less flawless than it was with the earlier version, but this > might be related to the fact master has moved a lot since then (from > v5.18-rcX to open merge window). > > Overall, it's still a net win over the status quo (broken boot). > > > Applying your patch on 664a393a2663a0f62fc1b18157ccae33dcdbb8c8 and > performing cold boots is mostly fine: > - without anything on the PCIe slot; > - with a PCIe→quad-USB extension board, a USB keyboard and a USB stick > (both work fine). > > However, with an empty PCIe slot, I'm no longer able to perform the > following (which was rock solid, and has been used in all my testing up > to now): > - boot the exact same Debian stable image as before (running v5.10.y if > that matters); > - deploy the patched kernel; > - enable serial console; > - reboot into the patched kernel. Hi Cyril, Thanks for the quick response. As you may have guessed our CM4 did not arrive yet although we did get the CM4 IO board. I don't know if you have the bandwidth to try one or both of these tests: (1) Same experiment except remove the V2 commit and use my V1 commit. Unless this is exactly what you tried before. (2) Same experiment except commenting out the call I made to regulator_bulk_free(). > > PCI-related messages, a call trace, and broken storage: > > [ 3.425331] brcm-pcie fd500000.pcie: host bridge /scb/pcie@7d500000 ranges: > [ 3.425353] brcm-pcie fd500000.pcie: No bus range found for /scb/pcie@7d500000, using [bus 00-ff] > [ 3.425388] brcm-pcie fd500000.pcie: MEM 0x0600000000..0x0603ffffff -> 0x00f8000000 > [ 3.425420] brcm-pcie fd500000.pcie: IB MEM 0x0000000000..0x003fffffff -> 0x0400000000 > [ 3.426229] brcm-pcie fd500000.pcie: PCI host bridge to bus 0000:00 > [ 3.426243] pci_bus 0000:00: root bus resource [bus 00-ff] > [ 3.426255] pci_bus 0000:00: root bus resource [mem 0x600000000-0x603ffffff] (bus address [0xf8000000-0xfbffffff]) > [ 3.426303] pci 0000:00:00.0: [14e4:2711] type 01 class 0x060400 > [ 3.426398] pci 0000:00:00.0: PME# supported from D0 D3hot > [ 3.428797] pci 0000:00:00.0: bridge configuration invalid ([bus 00-00]), reconfiguring > [ 3.745909] brcm-pcie fd500000.pcie: link down > [ 3.747915] pci_bus 0000:01: busn_res: [bus 01-ff] end is updated to 01 > [ 3.747944] pci 0000:00:00.0: PCI bridge to [bus 01] > [ 3.748294] pcieport 0000:00:00.0: PME: Signaling with IRQ 23 > [ 3.748691] pcieport 0000:00:00.0: AER: enabled with IRQ 23 > [ 3.749201] pci_bus 0000:01: busn_res: [bus 01] is released > [ 3.749462] pci_bus 0000:00: busn_res: [bus 00-ff] is released > … Does "..." here mean you removed some lines or that it hung? If you removed lines can you please post the full bootlog? I do not need to see the mmc0 sdhci errors though. > [ 5.617308] irq 35: nobody cared (try booting with the "irqpoll" option) > [ 5.617335] CPU: 0 PID: 127 Comm: systemd-udevd Not tainted 5.18.0+ #1 > [ 5.617350] Hardware name: Raspberry Pi Compute Module 4 Rev 1.0 (DT) > [ 5.617358] Call trace: > [ 5.617362] dump_backtrace+0xc0/0x130 > [ 5.617386] show_stack+0x24/0x70 > [ 5.617396] dump_stack_lvl+0x68/0x84 > [ 5.617415] dump_stack+0x18/0x34 > [ 5.617426] __report_bad_irq+0x54/0x16c > [ 5.617436] note_interrupt+0x324/0x41c > [ 5.617445] handle_irq_event+0xc0/0x180 > [ 5.617460] handle_fasteoi_irq+0xc8/0x1fc > [ 5.617468] generic_handle_domain_irq+0x38/0x50 > [ 5.617481] gic_handle_irq+0x68/0xa0 > [ 5.617489] call_on_irq_stack+0x2c/0x60 > [ 5.617500] do_interrupt_handler+0x88/0x90 > [ 5.617511] el0_interrupt+0x58/0x124 > [ 5.617526] __el0_irq_handler_common+0x18/0x2c > [ 5.617538] el0t_64_irq_handler+0x10/0x20 > [ 5.617549] el0t_64_irq+0x18c/0x190 > [ 5.617558] handlers: > [ 5.617563] [<(____ptrval____)>] sdhci_irq [sdhci] threaded [<(____ptrval____)>] sdhci_thread_irq [sdhci] > [ 5.617613] Disabling IRQ #35 > … > [ 15.581894] mmc0: Timeout waiting for hardware cmd interrupt. > [ 15.581914] mmc0: sdhci: ============ SDHCI REGISTER DUMP =========== > [ 15.581920] mmc0: sdhci: Sys addr: 0x00000000 | Version: 0x00001002 > [ 15.581931] mmc0: sdhci: Blk size: 0x00000000 | Blk cnt: 0x00000000 > [ 15.581937] mmc0: sdhci: Argument: 0x00000c00 | Trn mode: 0x00000000 > [ 15.581944] mmc0: sdhci: Present: 0x1fff0000 | Host ctl: 0x00000001 > [ 15.581951] mmc0: sdhci: Power: 0x0000000f | Blk gap: 0x00000080 > [ 15.581957] mmc0: sdhci: Wake-up: 0x00000000 | Clock: 0x00007d07 > [ 15.581964] mmc0: sdhci: Timeout: 0x00000000 | Int stat: 0x00018000 > [ 15.581971] mmc0: sdhci: Int enab: 0x00ff1003 | Sig enab: 0x00ff1003 > [ 15.581976] mmc0: sdhci: ACmd stat: 0x00000000 | Slot int: 0x00000001 > [ 15.581982] mmc0: sdhci: Caps: 0x45ee6432 | Caps_1: 0x0000a525 > [ 15.581988] mmc0: sdhci: Cmd: 0x0000341a | Max curr: 0x00080008 > [ 15.581996] mmc0: sdhci: Resp[0]: 0x00000000 | Resp[1]: 0x00000000 > [ 15.582001] mmc0: sdhci: Resp[2]: 0x00000000 | Resp[3]: 0x00000000 > [ 15.582005] mmc0: sdhci: Host ctl2: 0x00000000 > [ 15.582011] mmc0: sdhci: ADMA Err: 0x00000000 | ADMA Ptr: 0x00000000 > [ 15.582016] mmc0: sdhci: ============================================ > > This last part gets repeated over and over, and storage (external SD > card) never comes up. I can share fuller logs if that's desirable. I can the full bootlog? > [ 5.617308] irq 35: nobody cared (try booting with the "irqpoll" option) > [ 5.617335] CPU: 0 PID: 127 Comm: systemd-udevd Not tainted 5.18.0+ #1 > [ 5.617350] Hardware name: Raspberry Pi Compute Module 4 Rev 1.0 (DT) > [ 5.617358] Call trace: > [ 5.617362] dump_backtrace+0xc0/0x130 > [ 5.617386] show_stack+0x24/0x70 > [ 5.617396] dump_stack_lvl+0x68/0x84 > [ 5.617415] dump_stack+0x18/0x34 > [ 5.617426] __report_bad_irq+0x54/0x16c > [ 5.617436] note_interrupt+0x324/0x41c > [ 5.617445] handle_irq_event+0xc0/0x180 > [ 5.617460] handle_fasteoi_irq+0xc8/0x1fc > [ 5.617468] generic_handle_domain_irq+0x38/0x50 > [ 5.617481] gic_handle_irq+0x68/0xa0 > [ 5.617489] call_on_irq_stack+0x2c/0x60 > [ 5.617500] do_interrupt_handler+0x88/0x90 > [ 5.617511] el0_interrupt+0x58/0x124 > [ 5.617526] __el0_irq_handler_common+0x18/0x2c > [ 5.617538] el0t_64_irq_handler+0x10/0x20 > [ 5.617549] el0t_64_irq+0x18c/0x190 > [ 5.617558] handlers: > [ 5.617563] [<(____ptrval____)>] sdhci_irq [sdhci] threaded [<(____ptrval____)>] sdhci_thread_irq [sdhci] > [ 5.617613] Disabling IRQ #35 > … > [ 15.581894] mmc0: Timeout waiting for hardware cmd interrupt. > [ 15.581914] mmc0: sdhci: ============ SDHCI REGISTER DUMP =========== > [ 15.581920] mmc0: sdhci: Sys addr: 0x00000000 | Version: 0x00001002 > [ 15.581931] mmc0: sdhci: Blk size: 0x00000000 | Blk cnt: 0x00000000 > [ 15.581937] mmc0: sdhci: Argument: 0x00000c00 | Trn mode: 0x00000000 > [ 15.581944] mmc0: sdhci: Present: 0x1fff0000 | Host ctl: 0x00000001 > [ 15.581951] mmc0: sdhci: Power: 0x0000000f | Blk gap: 0x00000080 > [ 15.581957] mmc0: sdhci: Wake-up: 0x00000000 | Clock: 0x00007d07 > [ 15.581964] mmc0: sdhci: Timeout: 0x00000000 | Int stat: 0x00018000 > [ 15.581971] mmc0: sdhci: Int enab: 0x00ff1003 | Sig enab: 0x00ff1003 > [ 15.581976] mmc0: sdhci: ACmd stat: 0x00000000 | Slot int: 0x00000001 > [ 15.581982] mmc0: sdhci: Caps: 0x45ee6432 | Caps_1: 0x0000a525 > [ 15.581988] mmc0: sdhci: Cmd: 0x0000341a | Max curr: 0x00080008 > [ 15.581996] mmc0: sdhci: Resp[0]: 0x00000000 | Resp[1]: 0x00000000 > [ 15.582001] mmc0: sdhci: Resp[2]: 0x00000000 | Resp[3]: 0x00000000 > [ 15.582005] mmc0: sdhci: Host ctl2: 0x00000000 > [ 15.582011] mmc0: sdhci: ADMA Err: 0x00000000 | ADMA Ptr: 0x00000000 > [ 15.582016] mmc0: sdhci: ============================================ >> also test booting with irqpoll if that's desirable. Or anything else that > might help. I have seen this before and I do not think it is related to my V2 commit. Nonetheless, let us assume that it is related until we can prove otherwise. > > > I did check that applying the same patch on top of the v5.18 tag gives > good results (cold boots and reboots are fine, with or without an empty > PCIe slot, as that was the case during earlier test sessions), so I'd > guess something changed since then, and makes reboots more brittle than > they used to be. Okay, that's why I'd like to see if my v1 works and the v2 doesn't. That will tell me a lot. Kind regards, Jim Quinlan Broadcom STB > > I can also check applying the v1 patch on top of master and compare > results, to give a different perspective. > > But I'd also be happy to get some directions as to which test(s) would > be most beneficial, which would help me cut down on combinatorics. > > > Cheers, > -- > Cyril Brulebois (kibi@debian.org) <https://debamax.com/> > D-I release manager -- Release team member -- Freelance Consultant
On Sat, May 28, 2022 at 6:44 PM Jim Quinlan <jim2101024@gmail.com> wrote: > > commit 93e41f3fca3d ("PCI: brcmstb: Add control of subdevice voltage regulators") > Signed-off-by: Jim Quinlan <jim2101024@gmail.com> > introduced a regression on the PCIe RPi4 Compute Module. If the PCIe > root port DT node described in [2] was missing, no linkup would be attempted, > and subsequent accesses would cause a panic because this particular PCIe HW > causes a CPU abort on illegal accesses (instead of returning 0xffffffff). > > We fix this by allowing the DT root port node to be missing, as it behaved > before the original patchset messed things up. > > In addition, two small changes are made: > > 1. Having pci_subdev_regulators_remove_bus() call > regulator_bulk_free() in addtion to regulator_bulk_disable(). > 2. Having brcm_pcie_add_bus() return 0 if there is an > error in calling pci_subdev_regulators_add_bus(). > Instead, we dev_err() and turn on our refusal mode instead. > > It would be best if this commit were tested by someone with a Rpi CM4 > platform, as that is how the regression was found. I have only emulated > the problem and fix on different platform. > > Note that a bisection identified > > commit 830aa6f29f07 ("PCI: brcmstb: Split brcm_pcie_setup() into two funcs") > > as the first failing commit. This commit is a regression, but is unrelated > and was fixed by a subsequent commit in the original patchset. > > [1] https://bugzilla.kernel.org/show_bug.cgi?id=215925 > [2] Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml > > Fixes: 93e41f3fca3d ("PCI: brcmstb: Add control of subdevice voltage regulators") > Fixes: 830aa6f29f07 ("PCI: brcmstb: Split brcm_pcie_setup() into two funcs") > Link: https://bugzilla.kernel.org/show_bug.cgi?id=215925 Thorston -- I forgot to replace the bugzilla link; I'll get it on V3. -- Jim > Signed-off-by: Jim Quinlan <jim2101024@gmail.com> > --- > drivers/pci/controller/pcie-brcmstb.c | 43 +++++++++++++++++++-------- > 1 file changed, 30 insertions(+), 13 deletions(-) > > diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c > index ba5c120816b2..0839325f79ab 100644 > --- a/drivers/pci/controller/pcie-brcmstb.c > +++ b/drivers/pci/controller/pcie-brcmstb.c > @@ -540,29 +540,42 @@ static int pci_subdev_regulators_add_bus(struct pci_bus *bus) > > static int brcm_pcie_add_bus(struct pci_bus *bus) > { > - struct device *dev = &bus->dev; > - struct brcm_pcie *pcie = (struct brcm_pcie *) bus->sysdata; > + struct brcm_pcie *pcie; > int ret; > > - if (!dev->of_node || !bus->parent || !pci_is_root_bus(bus->parent)) > + /* > + * Right now we only alloc/enable regulators and initiate pcie link > + * when under the root port bus of the current domain. In the > + * future we may want to alloc/enable regulators under any port > + * device (e.g. a switch). > + */ > + if (!bus->parent || !pci_is_root_bus(bus->parent)) > return 0; > > ret = pci_subdev_regulators_add_bus(bus); > - if (ret) > - return ret; > + if (ret) { > + dev_err(pcie->dev, "failed to alloc/enable regulators\n"); > + goto err; > + } > > - /* Grab the regulators for suspend/resume */ > + /* Save the regulators for RC suspend/resume */ > + pcie = (struct brcm_pcie *) bus->sysdata; > pcie->sr = bus->dev.driver_data; > > + /* Attempt PCIe link-up */ > + if (brcm_pcie_linkup(pcie) == 0) > + return 0; > +err: > /* > - * If we have failed linkup there is no point to return an error as > - * currently it will cause a WARNING() from pci_alloc_child_bus(). > - * We return 0 and turn on the "refusal_mode" so that any further > - * accesses to the pci_dev just get 0xffffffff > + * If we have failed linkup or have an error when turning on > + * regulators, there is no point to return an error value to the > + * caller (pci_alloc_child_bus()) as it will summarily execute a > + * WARNING(). Instead, we turn on our "refusal_mode" and return 0 > + * so that any further PCIe accesses succeed but do nothing (reads > + * return 0xffffffff). If we do not turn on refusal mode, our > + * unforgiving PCIe HW will signal a CPU abort. > */ > - if (brcm_pcie_linkup(pcie) != 0) > - pcie->refusal_mode = true; > - > + pcie->refusal_mode = true; > return 0; > } > > @@ -570,13 +583,17 @@ static void pci_subdev_regulators_remove_bus(struct pci_bus *bus) > { > struct device *dev = &bus->dev; > struct subdev_regulators *sr = dev->driver_data; > + struct brcm_pcie *pcie; > > if (!sr || !bus->parent || !pci_is_root_bus(bus->parent)) > return; > > if (regulator_bulk_disable(sr->num_supplies, sr->supplies)) > dev_err(dev, "failed to disable regulators for downstream device\n"); > + regulator_bulk_free(sr->num_supplies, sr->supplies); > dev->driver_data = NULL; > + pcie = (struct brcm_pcie *) bus->sysdata; > + pcie->sr = NULL; > } > > /* Limits operation to a specific generation (1, 2, or 3) */ > -- > 2.17.1 >
On 29.05.22 18:52, Jim Quinlan wrote: > On Sat, May 28, 2022 at 6:44 PM Jim Quinlan <jim2101024@gmail.com> wrote: >> >> commit 93e41f3fca3d ("PCI: brcmstb: Add control of subdevice voltage regulators") > >> Signed-off-by: Jim Quinlan <jim2101024@gmail.com> >> introduced a regression on the PCIe RPi4 Compute Module. If the PCIe >> root port DT node described in [2] was missing, no linkup would be attempted, >> and subsequent accesses would cause a panic because this particular PCIe HW >> causes a CPU abort on illegal accesses (instead of returning 0xffffffff). >> >> We fix this by allowing the DT root port node to be missing, as it behaved >> before the original patchset messed things up. >> >> In addition, two small changes are made: >> >> 1. Having pci_subdev_regulators_remove_bus() call >> regulator_bulk_free() in addtion to regulator_bulk_disable(). >> 2. Having brcm_pcie_add_bus() return 0 if there is an >> error in calling pci_subdev_regulators_add_bus(). >> Instead, we dev_err() and turn on our refusal mode instead. >> >> It would be best if this commit were tested by someone with a Rpi CM4 >> platform, as that is how the regression was found. I have only emulated >> the problem and fix on different platform. >> >> Note that a bisection identified >> >> commit 830aa6f29f07 ("PCI: brcmstb: Split brcm_pcie_setup() into two funcs") >> >> as the first failing commit. This commit is a regression, but is unrelated >> and was fixed by a subsequent commit in the original patchset. >> >> [1] https://bugzilla.kernel.org/show_bug.cgi?id=215925 >> [2] Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml >> >> Fixes: 93e41f3fca3d ("PCI: brcmstb: Add control of subdevice voltage regulators") >> Fixes: 830aa6f29f07 ("PCI: brcmstb: Split brcm_pcie_setup() into two funcs") >> Link: https://bugzilla.kernel.org/show_bug.cgi?id=215925 > Thorston -- I forgot to replace the bugzilla link; I'll get it on V3. -- Jim Don't worry to much about these details that might matter for regzbot normally (the automatic handling of links to bugzilla ticket is sadly dysfunctional currently anyway). Just getting the issue fixed in the not-to-distant future is what I mainly care about. :-D Ciao Thorsten
Hi Cyril, Am 29.05.22 um 03:15 schrieb Cyril Brulebois: > Hi Jim, > > Jim Quinlan <jim2101024@gmail.com> (2022-05-28): >> commit 93e41f3fca3d ("PCI: brcmstb: Add control of subdevice voltage regulators") >> >> introduced a regression on the PCIe RPi4 Compute Module. If the PCIe >> root port DT node described in [2] was missing, no linkup would be attempted, >> and subsequent accesses would cause a panic because this particular PCIe HW >> causes a CPU abort on illegal accesses (instead of returning 0xffffffff). >> >> We fix this by allowing the DT root port node to be missing, as it behaved >> before the original patchset messed things up. >> >> In addition, two small changes are made: >> >> 1. Having pci_subdev_regulators_remove_bus() call >> regulator_bulk_free() in addtion to regulator_bulk_disable(). >> 2. Having brcm_pcie_add_bus() return 0 if there is an >> error in calling pci_subdev_regulators_add_bus(). >> Instead, we dev_err() and turn on our refusal mode instead. >> >> It would be best if this commit were tested by someone with a Rpi CM4 >> platform, as that is how the regression was found. I have only emulated >> the problem and fix on different platform. > Testing is less flawless than it was with the earlier version, but this > might be related to the fact master has moved a lot since then (from > v5.18-rcX to open merge window). > > Overall, it's still a net win over the status quo (broken boot). > > > Applying your patch on 664a393a2663a0f62fc1b18157ccae33dcdbb8c8 and > performing cold boots is mostly fine: > - without anything on the PCIe slot; > - with a PCIe→quad-USB extension board, a USB keyboard and a USB stick > (both work fine). > > However, with an empty PCIe slot, I'm no longer able to perform the > following (which was rock solid, and has been used in all my testing up > to now): > - boot the exact same Debian stable image as before (running v5.10.y if > that matters); > - deploy the patched kernel; > - enable serial console; > - reboot into the patched kernel. > > PCI-related messages, a call trace, and broken storage: > > [ 3.425331] brcm-pcie fd500000.pcie: host bridge /scb/pcie@7d500000 ranges: > [ 3.425353] brcm-pcie fd500000.pcie: No bus range found for /scb/pcie@7d500000, using [bus 00-ff] > [ 3.425388] brcm-pcie fd500000.pcie: MEM 0x0600000000..0x0603ffffff -> 0x00f8000000 > [ 3.425420] brcm-pcie fd500000.pcie: IB MEM 0x0000000000..0x003fffffff -> 0x0400000000 > [ 3.426229] brcm-pcie fd500000.pcie: PCI host bridge to bus 0000:00 > [ 3.426243] pci_bus 0000:00: root bus resource [bus 00-ff] > [ 3.426255] pci_bus 0000:00: root bus resource [mem 0x600000000-0x603ffffff] (bus address [0xf8000000-0xfbffffff]) > [ 3.426303] pci 0000:00:00.0: [14e4:2711] type 01 class 0x060400 > [ 3.426398] pci 0000:00:00.0: PME# supported from D0 D3hot > [ 3.428797] pci 0000:00:00.0: bridge configuration invalid ([bus 00-00]), reconfiguring > [ 3.745909] brcm-pcie fd500000.pcie: link down > [ 3.747915] pci_bus 0000:01: busn_res: [bus 01-ff] end is updated to 01 > [ 3.747944] pci 0000:00:00.0: PCI bridge to [bus 01] > [ 3.748294] pcieport 0000:00:00.0: PME: Signaling with IRQ 23 > [ 3.748691] pcieport 0000:00:00.0: AER: enabled with IRQ 23 > [ 3.749201] pci_bus 0000:01: busn_res: [bus 01] is released > [ 3.749462] pci_bus 0000:00: busn_res: [bus 00-ff] is released > … > [ 5.617308] irq 35: nobody cared (try booting with the "irqpoll" option) > [ 5.617335] CPU: 0 PID: 127 Comm: systemd-udevd Not tainted 5.18.0+ #1 > [ 5.617350] Hardware name: Raspberry Pi Compute Module 4 Rev 1.0 (DT) > [ 5.617358] Call trace: > [ 5.617362] dump_backtrace+0xc0/0x130 > [ 5.617386] show_stack+0x24/0x70 > [ 5.617396] dump_stack_lvl+0x68/0x84 > [ 5.617415] dump_stack+0x18/0x34 > [ 5.617426] __report_bad_irq+0x54/0x16c > [ 5.617436] note_interrupt+0x324/0x41c > [ 5.617445] handle_irq_event+0xc0/0x180 > [ 5.617460] handle_fasteoi_irq+0xc8/0x1fc > [ 5.617468] generic_handle_domain_irq+0x38/0x50 > [ 5.617481] gic_handle_irq+0x68/0xa0 > [ 5.617489] call_on_irq_stack+0x2c/0x60 > [ 5.617500] do_interrupt_handler+0x88/0x90 > [ 5.617511] el0_interrupt+0x58/0x124 > [ 5.617526] __el0_irq_handler_common+0x18/0x2c > [ 5.617538] el0t_64_irq_handler+0x10/0x20 > [ 5.617549] el0t_64_irq+0x18c/0x190 > [ 5.617558] handlers: > [ 5.617563] [<(____ptrval____)>] sdhci_irq [sdhci] threaded [<(____ptrval____)>] sdhci_thread_irq [sdhci] > [ 5.617613] Disabling IRQ #35 > … > [ 15.581894] mmc0: Timeout waiting for hardware cmd interrupt. > [ 15.581914] mmc0: sdhci: ============ SDHCI REGISTER DUMP =========== > [ 15.581920] mmc0: sdhci: Sys addr: 0x00000000 | Version: 0x00001002 > [ 15.581931] mmc0: sdhci: Blk size: 0x00000000 | Blk cnt: 0x00000000 > [ 15.581937] mmc0: sdhci: Argument: 0x00000c00 | Trn mode: 0x00000000 > [ 15.581944] mmc0: sdhci: Present: 0x1fff0000 | Host ctl: 0x00000001 > [ 15.581951] mmc0: sdhci: Power: 0x0000000f | Blk gap: 0x00000080 > [ 15.581957] mmc0: sdhci: Wake-up: 0x00000000 | Clock: 0x00007d07 > [ 15.581964] mmc0: sdhci: Timeout: 0x00000000 | Int stat: 0x00018000 > [ 15.581971] mmc0: sdhci: Int enab: 0x00ff1003 | Sig enab: 0x00ff1003 > [ 15.581976] mmc0: sdhci: ACmd stat: 0x00000000 | Slot int: 0x00000001 > [ 15.581982] mmc0: sdhci: Caps: 0x45ee6432 | Caps_1: 0x0000a525 > [ 15.581988] mmc0: sdhci: Cmd: 0x0000341a | Max curr: 0x00080008 > [ 15.581996] mmc0: sdhci: Resp[0]: 0x00000000 | Resp[1]: 0x00000000 > [ 15.582001] mmc0: sdhci: Resp[2]: 0x00000000 | Resp[3]: 0x00000000 > [ 15.582005] mmc0: sdhci: Host ctl2: 0x00000000 > [ 15.582011] mmc0: sdhci: ADMA Err: 0x00000000 | ADMA Ptr: 0x00000000 > [ 15.582016] mmc0: sdhci: ============================================ > > This last part gets repeated over and over, and storage (external SD > card) never comes up. I can share fuller logs if that's desirable. I can > also test booting with irqpoll if that's desirable. Or anything else that > might help. > > > I did check that applying the same patch on top of the v5.18 tag gives > good results (cold boots and reboots are fine, with or without an empty > PCIe slot, as that was the case during earlier test sessions), so I'd > guess something changed since then, and makes reboots more brittle than > they used to be. i think we should better trust the results based on the v5.18 tag. During the merge window, regressions from other subsystems are possible. Best regards > > I can also check applying the v1 patch on top of master and compare > results, to give a different perspective. > > But I'd also be happy to get some directions as to which test(s) would > be most beneficial, which would help me cut down on combinatorics. > > > Cheers, > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Hi Stefan, Stefan Wahren <stefan.wahren@i2se.com> (2022-05-30): > i think we should better trust the results based on the v5.18 tag. During > the merge window, regressions from other subsystems are possible. Alright, that looks like a great plan. Before getting your answer, I had tried taking the reboot part out of the equation, but I found out that even cold boots might fail with the mmc storage. I haven't been able to conduct a systematic testing of the patch on top of the v5.18 tag yet (say, 10 or 20 cold boots, and the same with reboots) due to strong work constraints these past few days, but that's definitely still on my short term todo list (hopefully before the end of the week). Sorry I didn't manage to get that lined up before Bjorn's pull request. Cheers,
On Thu, Jun 02, 2022 at 09:17:57PM +0200, Cyril Brulebois wrote: > ... > Sorry I didn't manage to get that lined up before Bjorn's pull request. No rush, if I had been on the ball, I would have done the reverts earlier so v5.18 didn't release with the regression.
On Thu, Jun 2, 2022 at 3:18 PM Cyril Brulebois <kibi@debian.org> wrote: >stm32mp157c-ev1.dts > Hi Stefan, > > Stefan Wahren <stefan.wahren@i2se.com> (2022-05-30): > > i think we should better trust the results based on the v5.18 tag. During > > the merge window, regressions from other subsystems are possible. > > Alright, that looks like a great plan. > > Before getting your answer, I had tried taking the reboot part out of > the equation, but I found out that even cold boots might fail with the > mmc storage. Hi Cyril, FWIW, I can deliberately reproduce the errors you observed by using an incorrect "interrupts" property for the sdhci device's DT node. It can also be triggered by removing its "clocks" property. However, if I do one of the above, the error will occur on every boot, but in your case (I think) you are seeing it sporadically. So that is peculiar. I've looked at the recent upstream commits for changes in the sdhci driver and also the relevant DT node and do not see anything obvious that might cause this. BTW, when you observe this error, can you please do a "cat /proc/interrupts" and post the results? Thanks & regards, Jim Quinlan Broadcom STB > > I haven't been able to conduct a systematic testing of the patch on top sdhci driver or the relevant DT node > of the v5.18 tag yet (say, 10 or 20 cold boots, and the same with > reboots) due to strong work constraints these past few days, but that's > definitely still on my short term todo list (hopefully before the end of > the week). > > Sorry I didn't manage to get that lined up before Bjorn's pull request. > > > Cheers, > -- > Cyril Brulebois (kibi@debian.org) <https://debamax.com/> > D-I release manager -- Release team member -- Freelance Consultant
diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c index ba5c120816b2..0839325f79ab 100644 --- a/drivers/pci/controller/pcie-brcmstb.c +++ b/drivers/pci/controller/pcie-brcmstb.c @@ -540,29 +540,42 @@ static int pci_subdev_regulators_add_bus(struct pci_bus *bus) static int brcm_pcie_add_bus(struct pci_bus *bus) { - struct device *dev = &bus->dev; - struct brcm_pcie *pcie = (struct brcm_pcie *) bus->sysdata; + struct brcm_pcie *pcie; int ret; - if (!dev->of_node || !bus->parent || !pci_is_root_bus(bus->parent)) + /* + * Right now we only alloc/enable regulators and initiate pcie link + * when under the root port bus of the current domain. In the + * future we may want to alloc/enable regulators under any port + * device (e.g. a switch). + */ + if (!bus->parent || !pci_is_root_bus(bus->parent)) return 0; ret = pci_subdev_regulators_add_bus(bus); - if (ret) - return ret; + if (ret) { + dev_err(pcie->dev, "failed to alloc/enable regulators\n"); + goto err; + } - /* Grab the regulators for suspend/resume */ + /* Save the regulators for RC suspend/resume */ + pcie = (struct brcm_pcie *) bus->sysdata; pcie->sr = bus->dev.driver_data; + /* Attempt PCIe link-up */ + if (brcm_pcie_linkup(pcie) == 0) + return 0; +err: /* - * If we have failed linkup there is no point to return an error as - * currently it will cause a WARNING() from pci_alloc_child_bus(). - * We return 0 and turn on the "refusal_mode" so that any further - * accesses to the pci_dev just get 0xffffffff + * If we have failed linkup or have an error when turning on + * regulators, there is no point to return an error value to the + * caller (pci_alloc_child_bus()) as it will summarily execute a + * WARNING(). Instead, we turn on our "refusal_mode" and return 0 + * so that any further PCIe accesses succeed but do nothing (reads + * return 0xffffffff). If we do not turn on refusal mode, our + * unforgiving PCIe HW will signal a CPU abort. */ - if (brcm_pcie_linkup(pcie) != 0) - pcie->refusal_mode = true; - + pcie->refusal_mode = true; return 0; } @@ -570,13 +583,17 @@ static void pci_subdev_regulators_remove_bus(struct pci_bus *bus) { struct device *dev = &bus->dev; struct subdev_regulators *sr = dev->driver_data; + struct brcm_pcie *pcie; if (!sr || !bus->parent || !pci_is_root_bus(bus->parent)) return; if (regulator_bulk_disable(sr->num_supplies, sr->supplies)) dev_err(dev, "failed to disable regulators for downstream device\n"); + regulator_bulk_free(sr->num_supplies, sr->supplies); dev->driver_data = NULL; + pcie = (struct brcm_pcie *) bus->sysdata; + pcie->sr = NULL; } /* Limits operation to a specific generation (1, 2, or 3) */
commit 93e41f3fca3d ("PCI: brcmstb: Add control of subdevice voltage regulators") introduced a regression on the PCIe RPi4 Compute Module. If the PCIe root port DT node described in [2] was missing, no linkup would be attempted, and subsequent accesses would cause a panic because this particular PCIe HW causes a CPU abort on illegal accesses (instead of returning 0xffffffff). We fix this by allowing the DT root port node to be missing, as it behaved before the original patchset messed things up. In addition, two small changes are made: 1. Having pci_subdev_regulators_remove_bus() call regulator_bulk_free() in addtion to regulator_bulk_disable(). 2. Having brcm_pcie_add_bus() return 0 if there is an error in calling pci_subdev_regulators_add_bus(). Instead, we dev_err() and turn on our refusal mode instead. It would be best if this commit were tested by someone with a Rpi CM4 platform, as that is how the regression was found. I have only emulated the problem and fix on different platform. Note that a bisection identified commit 830aa6f29f07 ("PCI: brcmstb: Split brcm_pcie_setup() into two funcs") as the first failing commit. This commit is a regression, but is unrelated and was fixed by a subsequent commit in the original patchset. [1] https://bugzilla.kernel.org/show_bug.cgi?id=215925 [2] Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml Fixes: 93e41f3fca3d ("PCI: brcmstb: Add control of subdevice voltage regulators") Fixes: 830aa6f29f07 ("PCI: brcmstb: Split brcm_pcie_setup() into two funcs") Link: https://bugzilla.kernel.org/show_bug.cgi?id=215925 Signed-off-by: Jim Quinlan <jim2101024@gmail.com> --- drivers/pci/controller/pcie-brcmstb.c | 43 +++++++++++++++++++-------- 1 file changed, 30 insertions(+), 13 deletions(-)