lkml.org 
[lkml]   [2008]   [Aug]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    SubjectRe: [PATCH 1/2] pata_legacy: export functionality to ide
    From
    On Wed, Aug 06, 2008 at 07:57:40PM +0400, Sergei Shtylyov wrote:
    > Boris Petkov wrote:
    >
    >>>> From: Borislav Petkov <petkovbb@gmail.com>
    >>>> Date: Sun, 3 Aug 2008 18:46:35 +0200
    >>>> Subject: [PATCH] ide-generic: handle probing of legacy io-ports v4
    >
    >>>> 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. The iobase checking code is adapted from
    >>>> drivers/ata/pata_legacy.c after converting hex pci ids into their
    >>>> corresponding
    >>>> macros in <linux/pci_ids.h>.
    >
    >>>> CC: Sergei Shtylyov <sshtylyov@ru.mvista.com>
    >>>> Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
    >
    >>> Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
    >
    >>>> diff --git a/drivers/ide/ide-generic.c b/drivers/ide/ide-generic.c
    >>>> index 8fe8b5b..efce159 100644
    >>>> --- a/drivers/ide/ide-generic.c
    >>>> +++ b/drivers/ide/ide-generic.c
    >
    >>> [...]
    >
    >>>> @@ -100,19 +101,69 @@ static const u16 legacy_bases[] = { 0x1f0, 0x170,
    >>>> 0x1e8, 0x168, 0x1e0, 0x160 };
    >>>> static const int legacy_irqs[] = { 14, 15, 11, 10, 8, 12 };
    >>>> #endif
    >>>> +static void ide_generic_check_pci_legacy_iobases(int *primary, int
    >>>> *secondary)
    >>>> +{
    >>>> + struct pci_dev *p = NULL;
    >>>> + u16 val;
    >>>> +
    >>>> + for_each_pci_dev(p) {
    >>>> + int r;
    >>>> +
    >>>> + for (r = 0; r < 6; r++) {
    >>>> + if (pci_resource_start(p, r) == 0x1f0)
    >>>> + *primary = 1;
    >>>> + if (pci_resource_start(p, r) == 0x170)
    >>>> + *secondary = 1;
    >>>> + }
    >
    >>> Would have been probably enough to test only BAR0/2, don't you think?
    >
    >> I assume you're referring to the legacy ioports fixup in
    >> drivers/pci/probe.c:pci_setup_device().
    >
    > And to the fact that the value 0x1f0 should only be ever seen in BAR0
    > and 0x170 in BAR2 even if they would have been read off the chips (some
    > chips have these values reading back even in legacy mode, and even could
    > malfunction if other values are written there), not fixed up there, and
    > certainly not in BAR1 or BAR3, so it's quite pointless to look in these
    > BARs too.

    So the comment in there saying that in some cases BAR0-3 could contain junk is a
    bogus? In other words, can we assume that one will always read 0x1f0 from BAR0
    and 0x170 from BAR2 in compatibility mode. If so, the check is even simpler:

    if (pci_resource_start(p, 0) == 0x1f0)
    *primary = 1;
    if (pci_resource_start(p, 2) == 0x170)
    *secondary = 1;


    --
    Regards/Gruss,
    Boris.


    \
     
     \ /
      Last update: 2008-08-06 21:51    [W:0.031 / U:1.484 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site