Re: [PATCH v19 00/10] PCI: EP: Add RC-to-EP doorbell with platform MSI controller

[Niklas Cassel <cassel@kernel.org>]

On Wed, Jul 02, 2025 at 06:57:23PM +0530, Manivannan Sadhasivam wrote:
> On Mon, Jun 09, 2025 at 12:34:12PM GMT, Frank Li wrote:
> 
> Frank, thanks for your persistence in pushing this series, really appreciated!
> I've left some comments, but no real blocker.
> 
> Unfortunately, I don't have access to my endpoint setup right now. So I'll go
> ahead with the Tested-by tag from Niklas once my comments are addressed.

(snip)

> > Changes in v6:
> > - add Niklas's test by tag

My Tested-by tag was added on v6, now it is v19 :)

To be comfortable of still having my Tested-by tag here,
I decided to test v19.

However I got this:

[ 3255.257047] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000040
[ 3255.257824] Mem abort info:
[ 3255.258069]   ESR = 0x0000000096000004
[ 3255.258398]   EC = 0x25: DABT (current EL), IL = 32 bits
[ 3255.258862]   SET = 0, FnV = 0
[ 3255.259147]   EA = 0, S1PTW = 0
[ 3255.259423]   FSC = 0x04: level 0 translation fault
[ 3255.259849] Data abort info:
[ 3255.260102]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
[ 3255.260580]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[ 3255.261020]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[ 3255.261483] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000100a03000
[ 3255.262045] [0000000000000040] pgd=0000000000000000, p4d=0000000000000000
[ 3255.262639] Internal error: Oops: 0000000096000004 [#1]  SMP
[ 3255.263132] Modules linked in: rk805_pwrkey hantro_vpu v4l2_jpeg v4l2_vp9 v4l2_h264 v4l2_mem2mem videobuf2_v4l2 videobuf2_dma_contig videobuf2_memops videobuf2_common vidf
[ 3255.265357] CPU: 5 UID: 0 PID: 213 Comm: ln Not tainted 6.16.0-rc1+ #233 PREEMPT 
[ 3255.266009] Hardware name: Radxa ROCK 5B (DT)
[ 3255.266388] pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 3255.266995] pc : pci_epf_bind+0x160/0x240
[ 3255.267350] lr : pci_epf_bind+0x40/0x240
[ 3255.267694] sp : ffff800081593c30
[ 3255.267983] x29: ffff800081593c30 x28: ffff0001024b2300 x27: ffff000102fc2800
[ 3255.268606] x26: ffff00010191e000 x25: ffff000100504098 x24: ffff000107b8ec80
[ 3255.269228] x23: ffff000104cf3578 x22: 0000000000000000 x21: 0000000000000000
[ 3255.269850] x20: ffff000104cf3000 x19: ffff000104cf3578 x18: 0000000000000000
[ 3255.270472] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
[ 3255.271093] x14: 0000000000000000 x13: ffff00010245c037 x12: ffff800081593b94
[ 3255.271715] x11: 0000000528aa6179 x10: 0000000000000002 x9 : ffffa2593ce92b30
[ 3255.272336] x8 : 00000031636e7566 x7 : 00000000ffffbe12 x6 : 0000000000000003
[ 3255.272958] x5 : ffff000102413f78 x4 : ffff000102413f08 x3 : 0000000000000000
[ 3255.273580] x2 : ffff0001024b2300 x1 : 0000000000000000 x0 : ffff000104cf3000
[ 3255.274201] Call trace:
[ 3255.274416]  pci_epf_bind+0x160/0x240 (P)
[ 3255.274767]  pci_epc_epf_link+0x54/0xb0
[ 3255.275104]  configfs_symlink+0x208/0x540
[ 3255.275457]  vfs_symlink+0x158/0x1e0
[ 3255.275770]  do_symlinkat+0x8c/0x138
[ 3255.276083]  __arm64_sys_symlinkat+0x7c/0xc8
[ 3255.276455]  invoke_syscall.constprop.0+0x48/0x100
[ 3255.276874]  el0_svc_common.constprop.0+0x40/0xe8
[ 3255.277285]  do_el0_svc+0x24/0x38
[ 3255.277575]  el0_svc+0x34/0x100
[ 3255.277852]  el0t_64_sync_handler+0x10c/0x140
[ 3255.278233]  el0t_64_sync+0x198/0x1a0
[ 3255.278554] Code: a9446bf9 394ff280 b902aa80 aa1403e0 (f94022a1) 
[ 3255.279085] ---[ end trace 0000000000000000 ]---


Seems to be from patch 1/10:

(gdb) l *(pci_epf_bind+0x160)
0xffff800080892c50 is in pci_epf_bind (drivers/pci/endpoint/pci-epf-core.c:132).
127                             goto ret;
128                     epf_vf->is_bound = true;
129             }
130
131             epf->dev.id = PCI_EPF_DEVID(epf->func_no, 0);
132             device_set_of_node_from_dev(&epf->dev, epc->dev.parent);
133             ret = epf->driver->ops->bind(epf);
134             if (ret)
135                     goto ret;
136             epf->is_bound = true;


I can see that there is a lot of discussion on patch 1/10 already,
but please drop my Tested-by tag until this has been fixed.

Feel free to CC me on v20 of this series, if the problem is fixed,
I will provide my Tested-by tag once again.


Kind regards,
Niklas