linux-kernel - Re: [PATCH 5/5] drivers: mfd: Fix resource request for [mem 0x00000000]

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Message-ID: <1352399063.2309.6.camel@thor>
Date:	Thu, 08 Nov 2012 13:24:23 -0500
From:	Peter Hurley <peter@...leysoftware.com>
To:	Aaron Sierra <asierra@...-inc.com>
Cc:	Peter Tyser <ptyser@...-inc.com>,
	Samuel Ortiz <sameo@...ux.intel.com>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 5/5] drivers: mfd: Fix resource request for [mem
 0x00000000]

On Thu, 2012-11-08 at 11:04 -0600, Aaron Sierra wrote:
> > The older southbridges supported by the lpc_ich driver do not
> > provide memory-mapped space of the root complex. The driver
> > correctly avoids computing the iomem address in this case, yet
> > submits a zeroed resource request anyway (via mfd_add_devices()).
> > 
> > Remove the iomem resource from the resource array submitted to the
> > mfd core for the older southbridges.
> > 
> 
> Peter, thanks for catching this.
> 
> > +	} else {
> > +		/* So don't register iomem for TCO ver 1 */
> > +		--lpc_ich_cells[LPC_WDT].num_resources;
> 
> My only complaint is that pre-decrementing num_resources isn't
> necessary and doesn't match the other cases where num_resources is
> decremented (post-decremented), like here:
> 
>         if (!base_addr) {
>                 dev_err(&dev->dev, "I/O space for ACPI uninitialized\n");
>                 lpc_ich_cells[LPC_GPIO].num_resources--;
>                 goto gpe0_done;
>         }

Sorry, C++ force-of-habit. How's this instead?  (please note, I also
retitled the patch to refer to lpc_ich specifically)

-- >8 --
Subject: [PATCH v2 5/5] mfd: lpc_ich: Fix resource request for [mem 0x00000000]

The older southbridges supported by the lpc_ich driver do not
provide memory-mapped space of the root complex. The driver
correctly avoids computing the iomem address in this case, yet
submits a zeroed resource request anyway (via mfd_add_devices()).

Remove the iomem resource from the resource array submitted to the
mfd core for the older southbridges.

Cc: Aaron Sierra <asierra@...-inc.com>
Cc: Peter Tyser <ptyser@...-inc.com>
Cc: Samuel Ortiz <sameo@...ux.intel.com>
Signed-off-by: Peter Hurley <peter@...leysoftware.com>
---

v2: post-decrement to match existing style
    retitle patch subject

 drivers/mfd/lpc_ich.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/mfd/lpc_ich.c b/drivers/mfd/lpc_ich.c
index a22544f..f507c09 100644
--- a/drivers/mfd/lpc_ich.c
+++ b/drivers/mfd/lpc_ich.c
@@ -842,6 +842,9 @@ static int __devinit lpc_ich_init_wdt(struct pci_dev *dev,
 		res = wdt_mem_res(ICH_RES_MEM_GCS);
 		res->start = base_addr + ACPIBASE_GCS_OFF;
 		res->end = base_addr + ACPIBASE_GCS_END;
+	} else {
+		/* So don't register iomem for TCO ver 1 */
+		lpc_ich_cells[LPC_WDT].num_resources--;
 	}
 
 	lpc_ich_finalize_cell(&lpc_ich_cells[LPC_WDT], id);
-- 
1.8.0




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