On Tue, Nov 6, 2018 at 2:35 PM Anatolij Gustschin <agust@xxxxxxx> wrote:
Hi Anatolij,
>
> Currently registering CvP managers works only for first probed CvP
> device, for all other devices it is refused due to duplicated chkcfg
> sysfs entry:
>
> fpga_manager fpga3: Altera CvP FPGA Manager @0000:0c:00.0 registered
> sysfs: cannot create duplicate filename '/bus/pci/drivers/altera-cvp/chkcfg'
Shouldn't this have been a file under /sys/class/fpga_manager/fpga0/
instead? This is a control per-device not per driver.
> CPU: 0 PID: 3808 Comm: bash Tainted: G O 4.19.0-custom+ #5
> Call Trace:
> dump_stack+0x46/0x5b
> sysfs_warn_dup+0x53/0x60
> sysfs_add_file_mode_ns+0x16d/0x180
> sysfs_create_file_ns+0x51/0x60
> altera_cvp_probe+0x16f/0x2a0 [altera_cvp]
> local_pci_probe+0x3f/0xa0
> ? pci_match_device+0xb1/0xf0
> pci_device_probe+0x116/0x170
> really_probe+0x21b/0x2c0
> driver_probe_device+0x4b/0xe0
> bind_store+0xcb/0x130
> kernfs_fop_write+0xfd/0x180
> __vfs_write+0x21/0x150
> ? selinux_file_permission+0xdc/0x130
> vfs_write+0xa8/0x1a0
> ? find_vma+0xd/0x60
> ksys_write+0x3d/0x90
> do_syscall_64+0x44/0xf0
> entry_SYSCALL_64_after_hwframe+0x44/0xa9
> ...
> altera-cvp 0000:0c:00.0: Can't create sysfs chkcfg file
> fpga_manager fpga3: fpga_mgr_unregister Altera CvP FPGA Manager @0000:0c:00.0
>
> Skip chkcfg creation for all but first probed device. Remove chkcfg
> interface when last potential user has gone.
>
> Signed-off-by: Anatolij Gustschin <agust@xxxxxxx>
> ---
> drivers/fpga/altera-cvp.c | 22 +++++++++++++++-------
> 1 file changed, 15 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c
> index 144fa2a4d4cc..381d0c42450f 100644
> --- a/drivers/fpga/altera-cvp.c
> +++ b/drivers/fpga/altera-cvp.c
> @@ -60,6 +60,7 @@
>
> /* Optional CvP config error status check for debugging */
> static bool altera_cvp_chkcfg;
> +static unsigned int altera_cvp_cnt;
>
> struct altera_cvp_conf {
> struct fpga_manager *mgr;
> @@ -466,12 +467,15 @@ static int altera_cvp_probe(struct pci_dev *pdev,
> if (ret)
> goto err_unmap;
>
> - ret = driver_create_file(&altera_cvp_driver.driver,
> - &driver_attr_chkcfg);
> - if (ret) {
> - dev_err(&pdev->dev, "Can't create sysfs chkcfg file\n");
> - fpga_mgr_unregister(mgr);
> - goto err_unmap;
> + if (!altera_cvp_cnt++) {
> + ret = driver_create_file(&altera_cvp_driver.driver,
> + &driver_attr_chkcfg);
In the review, I didn't catch that this was adding a driver file
instead of a device file.
> + if (ret) {
> + dev_err(&pdev->dev, "Can't create sysfs chkcfg file\n");
> + fpga_mgr_unregister(mgr);
> + altera_cvp_cnt--;
> + goto err_unmap;
> + }
> }
>
> return 0;
> @@ -492,7 +496,11 @@ static void altera_cvp_remove(struct pci_dev *pdev)
> struct altera_cvp_conf *conf = mgr->priv;
> u16 cmd;
>
> - driver_remove_file(&altera_cvp_driver.driver, &driver_attr_chkcfg);
> + if (!--altera_cvp_cnt) {
> + driver_remove_file(&altera_cvp_driver.driver,
> + &driver_attr_chkcfg);
> + }
> +
> fpga_mgr_unregister(mgr);
> if (conf->map)
> pci_iounmap(pdev, conf->map);
> --
> 2.17.1
>
Thanks,
Alan
