Re: [PATCH v2 3/4] watchdog: iTCO_wdt: Fix PMC GCR memory mapping failure

[sathyanarayanan kuppuswamy]

Hi Andy,


On 03/17/2017 11:38 AM, Andy Shevchenko wrote:
> On Fri, Mar 17, 2017 at 7:37 PM, sathyanarayanan kuppuswamy
> <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx> wrote:
> > On 03/17/2017 07:25 AM, Andy Shevchenko wrote:
> > > On Fri, Mar 17, 2017 at 3:40 PM, Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
> > > > On 03/17/2017 04:43 AM, Rajneesh Bhardwaj wrote:
> > > > > On Thu, Mar 16, 2017 at 05:41:35PM -0700, Kuppuswamy Sathyanarayanan
> > > > > wrote:
> > > I already asked once [1] to fix up the mess we have in PDx86 regarding SCU
> > > IPC.
> > > (PMC IPC how it's called is actually just a [main] part of SCU in newer
> > > SoCs).
> > >
> > > Rajneesh, Kuppuswamy,
> > > please pay attention on the below.
> > >
> > > We have two libraries doing almost the same (basics) one for old
> > > platforms, one for new.
> > >
> > > My vision what should be done before we go further is:
> > > 1. Split out common part from intel_scu_ipc and intel_pmc_ipc to some
> > > library.
> > I think we should create MFD driver for PMC and remove the redundant
> > resource and platform device creation codes.
> > Yes, there is common code in IPC implementation between scu_ipc and pmc_ipc
> > code. This needs be modularized.
> >
> > I can work on it and send a RFC patch for this cleanup. But it could take
> > more time for merging this cleanup patch.
> > So I think, in the mean time, we should merge this watchdog fix first to
> > remove iTCO watchdog device probe issue.
> I have heard already such excuses. Let's consider this as a "Last
> Chinese Warning".
>
> So, we consider reviewing applying *already floating around* patches
> in exchange to looking forward for clean up next.
> Do we have a deal?
Deal.
> Before you are going to implement anything in the code, please, share
> a document (architectural point of view) how you would see things
> should be done.
> Also consider to address PMC (Atom drivers) and P-Unit drivers which
> are related to SCU / IPC to have some structure.
Will send out the design document summarizing the issues we want to 
solve and a proposed design model.
> > > 2. Move headers to linux/platform_data/x86 for sharing with drivers
> > > that are supporting non-Intel / not-newest-Intel hardware.
> > > 3. Fix the mess inside the intel_pmc_ipc code (like use devm_()
> > > helpers where it makes sense, no use of global variables, etc)
> > Agreed.
> > > On top of that
> > > 4. Fix up Whiskey Cove PMIC code (See Hans' message [2] for the details)
> > >
> > > [1] Oops, it happened on internal mailing list Jan 27. And mentioned
> > > publicly after in a review on some patch here.
> > > [2] http://lkml.iu.edu/hypermail/linux/kernel/1702.3/01408.html

--
Sathyanarayanan Kuppuswamy
Android kernel developer