On Tue, Jun 08, 2021 at 11:18:53AM +0530, Amey Narkhede wrote:
> Add reset_method sysfs attribute to enable user to
> query and set user preferred device reset methods and
> their ordering.
> + Writing the name or comma separated list of names of any of
> + the device supported reset methods to this file will set the
> + reset methods and their ordering to be used when resetting
> + the device.
> + while ((name = strsep(&options, ",")) != NULL) {
> + if (sysfs_streq(name, ""))
> + continue;
> +
> + name = strim(name);
> +
> + for (i = 0; i < PCI_RESET_METHODS_NUM; i++) {
> + if (reset_methods[i] &&
> + sysfs_streq(name, pci_reset_fn_methods[i].name)) {
> + reset_methods[i] = prio--;
> + break;
> + }
> + }
> +
> + if (i == PCI_RESET_METHODS_NUM) {
> + kfree(options);
> + return -EINVAL;
> + }
> + }
Asking again since we didn't get this clarified before. The above
tells me that "reset_methods" allows the user to control the *order*
in which we try reset methods.
Consider the following two uses:
(1) # echo bus,flr > reset_methods
(2) # echo flr,bus > reset_methods
Do these have the same effect or not?
If "reset_methods" allows control over the order, I expect them to be
different: (1) would try a bus reset and, if the bus reset failed, an
FLR, while (2) would try an FLR and, if the FLR failed, a bus reset.
