linux-kernel - Re: [PATCH 2/2] ide-generic: handle probing of legacy io-ports

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Date:	Sun, 3 Aug 2008 16:45:39 +0200
From:	Borislav Petkov <petkovbb@...glemail.com>
To:	Bartlomiej Zolnierkiewicz <bzolnier@...il.com>
Cc:	alan@...hat.com, linux-kernel@...r.kernel.org,
	linux-ide@...r.kernel.org
Subject: Re: [PATCH 2/2] ide-generic: handle probing of legacy io-ports

On Sun, Aug 03, 2008 at 04:11:10PM +0200, Bartlomiej Zolnierkiewicz wrote:
> 
> On Sunday 03 August 2008, Borislav Petkov wrote:
> > From: Borislav Petkov <petkovbb@...il.com>
> > Date: Sun, 3 Aug 2008 09:28:53 +0200
> > Subject: [PATCH 2/2] ide-generic: handle probing of legacy io-ports
> > 
> > Avoid probing the io-ports in case an IDE PCI controller is present and it uses
> > the legacy iobases. If we still want to enforce the probing, we do
> > 
> > ide_generic.probe_mask=0x3f
> > 
> > on the kernel command line.
> > 
> > Signed-off-by: Borislav Petkov <petkovbb@...il.com>
> 
> Thanks for reworking the patch, looks much better now.
> 
> There are still some issues to address though.
> 
> > ---
> >  drivers/ide/ide-generic.c |   23 ++++++++++++++++++-----
> >  1 files changed, 18 insertions(+), 5 deletions(-)
> > 
> > diff --git a/drivers/ide/ide-generic.c b/drivers/ide/ide-generic.c
> > index 8fe8b5b..7d79616 100644
> > --- a/drivers/ide/ide-generic.c
> > +++ b/drivers/ide/ide-generic.c
> > @@ -27,7 +27,7 @@
> >  
> >  #define DRV_NAME	"ide_generic"
> >  
> > -static int probe_mask = 0x03;
> > +static int probe_mask = 0x00;
> 
> No need to initialize it now.

right, static.

> >  module_param(probe_mask, int, 0);
> >  MODULE_PARM_DESC(probe_mask, "probe mask for legacy ISA IDE ports");
> >  
> > @@ -105,18 +105,31 @@ static int __init ide_generic_init(void)
> >  	hw_regs_t hw[MAX_HWIFS], *hws[MAX_HWIFS];
> >  	struct ide_host *host;
> >  	unsigned long io_addr;
> > -	int i, rc;
> > +	int i, rc, dummy, primary = 0, secondary = 0;
> >  
> >  #ifdef CONFIG_MIPS
> >  	if (!ide_probe_legacy())
> >  		return -ENODEV;
> >  #endif
> > -	printk(KERN_INFO DRV_NAME ": please use \"probe_mask=0x3f\" module "
> > -			 "parameter for probing all legacy ISA IDE ports\n");
> > +	ata_legacy_check_iobases(&primary, &secondary, &dummy);
> > +
> > +	if (primary) {
> 
> Shouldn't this also check for secondary?

you don't have to since primary is set to one in all cases.

> > +		if (probe_mask) {
> > +			printk(KERN_WARNING "%s: enforcing probing of io ports "
> > +			       "upon user request.\n", DRV_NAME);
> > +			primary = 0;
> > +			secondary = 0;
> > +		} else
> > +			printk(KERN_INFO DRV_NAME ": please use "
> > +			       \"probe_mask=0x3f\" module parameter for probing"
> > +			       "all legacy ISA IDE ports\n");
> 
> Help message is no longer printed for !primary
> (we always want to have it unless probe_mask is set).

How about moving that info to Documentation/ide/ide.txt instead? Do we want to
issue that on every boot, seems like a too unimportant message to be in the
bootlog to me...

> > +
> > +	} else
> > +		probe_mask = 0x3;
> 
> I think this was meant to be 'probe_mask |= 3;'?

true.

> >  	memset(hws, 0, sizeof(hw_regs_t *) * MAX_HWIFS);
> >  
> > -	for (i = 0; i < ARRAY_SIZE(legacy_bases); i++) {
> > +	for (i = primary + secondary; i < ARRAY_SIZE(legacy_bases); i++) {
> 
> No need for primary/secondary checking here now as everything
> is controlled by probe_mask.
> 
> Thus we can check for probe_mask first in the previous chunk
> and it can be rewritten/simplified to something like:
> 
> 	ata_legacy_check_iobases(&primary, &secondary, &dummy);
> 
> 	if (probe_mask == 0) {
> 		printk(KERN_INFO DRV_NAME ": please use "
> 		       \"probe_mask=0x3f\" module parameter for probing"
> 		       "all legacy ISA IDE ports\n");
> 
> 		if (primary == 0)
> 			probe_mask |= 1;
> 
> 		if (secondary == 0)
> 			probe_mask |= 2;

True, this version is more readable. Reworked one coming up :) ...

-- 
Regards/Gruss,
    Boris.
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