On 4 February 2015 at 17:14, Rafael J. Wysocki <rjw@xxxxxxxxxxxxx> wrote: > On Wednesday, February 04, 2015 09:56:20 AM Ashwin Chaugule wrote: >> Hi Rafael, >> >> On 4 February 2015 at 08:48, Rafael J. Wysocki <rjw@xxxxxxxxxxxxx> wrote: >> > On Tuesday, February 03, 2015 09:44:36 PM Cristian wrote: >> >> 2015-02-03 12:11 GMT-03:00 Rafael J. Wysocki <rjw@xxxxxxxxxxxxx>: >> >> > On Tuesday, February 03, 2015 10:40:00 AM Cristian wrote: >> > >> > So it looks like you build the PCC mailbox driver which is new in 3.19-rc and >> > that driver fails to load, because it doesn't find hardware to work with. >> > >> > The message is harmless, but it also is not useful. The driver in question >> > seems to be overly verbose to me in general. >> >> Apologies. Looks like leftover from some early "printk" style debugging. :) > > Well, does that mean I should apply the patch below? Sure. Thanks. > >> > The patch below should make the message go away unless the printing of debug >> > messages is on. >> > >> > Ashwin, that whole thing requires cleaning up: >> > - It prints uninteresting debug messages with KERN_ERR or warning priority in >> > *many* places. >> > - The error codes from acpi_pcc_probe() are ignored, so why bother to return >> > any error codes from there? >> > - If platform_create_bundle() fails, the debug message doesn't tell us the >> > reason, so why bother to print it? >> > >> > I'm not going to consider any users of this for merging before that cleanup >> > happens. >> >> In V4 of the CPPC patchset I've simplified the PCC code a lot which >> should make many of the prints go away. Can we consider that patch >> (I'll add any more pr_debugs to it) or would you prefer having a >> separate cleanup patch for this? > > This is a patch for the mailbox subsystem maintainer to consider. If it is > accepted and if there are any of these excessvely verbose messages still present, > I'll expect them to be fixed in a separate patch. Ok. > > I have one more concern about this driver. Namely, what benefit is there to > people like Cristian from it at all? Its of use only if they have a PCC client (MPST, CPPC, RAS) driver. Looks like PCC was explicitly enabled in this kernel. config PCC bool "Platform Communication Channel Driver" depends on ACPI help ACPI 5.0+ spec defines a generic mode of communication between the OS and a platform such as the BMC. This medium (PCC) is typically used by CPPC (ACPI CPU Performance management), RAS (ACPI reliability protocol) and MPST (ACPI Memory power states). Select this driver if your platform implements the PCC clients mentioned above. Thanks, Ashwin -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
