Messages in this thread | | | Date | Sat, 2 May 2015 08:00:51 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH v1] x86: punit_atom: punit device state debug driver |
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* Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> wrote:
> The patch adds a debug driver, which dumps the power states > of all the North complex (NC) devices. This debug interface is > useful to figure out the NC IPs which blocks the S0ix > transitions on the platform. This is extremely useful during > enabling PM on customer platforms and derivatives.
Looks useful.
> This submission not a complete rewrite from the original > submission from Kumar P, Mahesh <mahesh.kumar.p.intel.com>. > https://lkml.org/lkml/2014/11/5/367
This sentence does not parse. Did you mean 'is a complete rewrite'?
> +config PUNIT_ATOM_DEBUG > + tristate "ATOM Punit debug driver" > + depends on DEBUG_FS > + select IOSF_MBI > + ---help--- > + This is a debug driver, which gets the power states > + of all Punit North Complex devices.The power states of > + each IP is exposed as part of the debugfs interface.
What is an 'IP'?
Also:
s/devices.The /devices. The
> + > endmenu > diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile > index cdb1b70..2ecbd55 100644 > --- a/arch/x86/kernel/Makefile > +++ b/arch/x86/kernel/Makefile > @@ -110,6 +110,7 @@ obj-$(CONFIG_PERF_EVENTS) += perf_regs.o > obj-$(CONFIG_TRACING) += tracepoint.o > obj-$(CONFIG_IOSF_MBI) += iosf_mbi.o > obj-$(CONFIG_PMC_ATOM) += pmc_atom.o > +obj-$(CONFIG_PUNIT_ATOM_DEBUG) += punit_atom_debug.o > > ### > # 64 bit specific files > diff --git a/arch/x86/kernel/punit_atom_debug.c b/arch/x86/kernel/punit_atom_debug.c
Please put this somewhere suitable in arch/x86/platform/.
> +/* > + * Intel SOC Punit device state debug driver > + * Copyright (c) 2015, Intel Corporation.
Would be nice to add a blurb about what 'Intel SOC Punit' systems are. There doesn't seem to be anything in the kernel source about it, so you have a golden opportunity here.
> +#define PUNIT_PORT 0x04 > +#define PWRGT_STATUS 0x61 /* Power gate status reg */ > +#define VED_SS_PM0 0x32 /* Subsystem config/status Video */ > +#define ISP_SS_PM0 0x39 /* Subsystem config/status ISP */ > +#define MIO_SS_PM 0x3B /* Subsystem config/status MIO */ > +#define SSS_SHIFT 24 > +#define RENDER_POS 0 > +#define MEDIA_POS 2 > +#define VLV_DISPLAY_POS 6 > +#define CHT_DSP_SSS 0x36 /* Subsystem config/status DSP */ > +#define CHT_DSP_SSS_POS 16
All the magic constants need some explanation for humans, not just some.
> +static const struct punit_device punit_device_byt[] = { > + { "GFX RENDER", PWRGT_STATUS, RENDER_POS }, > + { "GFX MEDIA", PWRGT_STATUS, MEDIA_POS }, > + { "DISPLAY", PWRGT_STATUS, VLV_DISPLAY_POS }, > + { "VED", VED_SS_PM0, SSS_SHIFT}, > + { "ISP", ISP_SS_PM0, SSS_SHIFT}, > + { "MIO", MIO_SS_PM, SSS_SHIFT}, > + { NULL} > +}; > + > +static const struct punit_device punit_device_cht[] = { > + { "GFX RENDER", PWRGT_STATUS, RENDER_POS }, > + { "GFX MEDIA", PWRGT_STATUS, MEDIA_POS }, > + { "DSP", CHT_DSP_SSS, CHT_DSP_SSS_POS }, > + { "VED", VED_SS_PM0, SSS_SHIFT}, > + { "ISP", ISP_SS_PM0, SSS_SHIFT}, > + { "MIO", MIO_SS_PM, SSS_SHIFT}, > + { NULL} > +};
Please align such initialization tables vertically, like you did here:
> +static const struct file_operations punit_dev_state_ops = { > + .open = punit_dev_state_open, > + .read = seq_read, > + .llseek = seq_lseek, > + .release = single_release, > +};
> + punit_dbg_file = debugfs_create_dir("punit_atom", NULL); > + if (!punit_dbg_file) > + return -ENXIO; > + > + dev_state = debugfs_create_file("dev_state", S_IFREG | S_IRUGO, > + punit_dbg_file, NULL, > + &punit_dev_state_ops);
So why isn't something that is declaradly a power state dump, called "power_state" or "dev_power_state"?
> +MODULE_AUTHOR("Kumar P, Mahesh <mahesh.kumar.p.intel.com>"); > +MODULE_DESCRIPTION("Driver for Punit devices states debugging"); > +MODULE_LICENSE("GPL v2");
Btw., you can have multiple MODULE_AUTHOR() lines, so you can credit yourself as well. Take a look at drivers/net/wireless/at76c50x-usb.c's MODULE_AUTHOR() for grins.
Thanks,
Ingo
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