Hi,
What do you think, would it be better just to left the check for all
x86 32-bit hardware?.
2014-07-18 11:31 GMT+04:00 Ondrej Zary <li...@rainbow-software.org>:
> On Friday 18 July 2014, mat...@sai.msu.ru wrote:
>> From: "Matwey V. Kornilov" <mat...@sai.msu.ru>
>>
>> The code in intel_bug_present is known to produce much false-positives.
>> It is believed that the affected by the bug hardware are used with either
>> Intel 80486 or Pentium.
>>
>> Perform the check only when the kernel configured as CONFIG_X86_32,
>> then use cpuinfo_x86 of the first available CPU to check the model
>> and run initial check code.
>>
>> Suggested-by: One Thousand Gnomes <gno...@lxorguk.ukuu.org.uk>
>> Tested-by: Heiko Andreas Sommer <hsom...@eso.org>
>> Signed-off-by: Matwey V. Kornilov <mat...@sai.msu.ru>
>> ---
>> drivers/parport/parport_pc.c | 21 ++++++++++++++++++++-
>> 1 file changed, 20 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/parport/parport_pc.c b/drivers/parport/parport_pc.c
>> index a6eaafb..6b28f9f 100644
>> --- a/drivers/parport/parport_pc.c
>> +++ b/drivers/parport/parport_pc.c
>> @@ -65,6 +65,7 @@
>> #include <linux/parport_pc.h>
>> #include <linux/via.h>
>> #include <asm/parport.h>
>> +#include <asm/processor.h>
>>
>> #define PARPORT_PC_MAX_PORTS PARPORT_MAX
>>
>> @@ -1702,7 +1703,11 @@ static int parport_ECP_supported(struct parport *pb)
>> }
>> #endif
>>
>> -static int intel_bug_present(struct parport *pb)
>> +/* It is believed that CPU model correlates with buggy LPT chipset model.
>> + Here we check that or CPU is elder than Pentium Pro: either 80486 or
>> Pentium. + If it is then we perform The Check. */
>> +#ifdef CONFIG_X86_32
>> +static int intel_bug_present_check_epp(struct parport *pb)
>> {
>> const struct parport_pc_private *priv = pb->private_data;
>> int bug_present = 0;
>> @@ -1725,6 +1730,20 @@ static int intel_bug_present(struct parport *pb)
>>
>> return bug_present;
>> }
>> +static int intel_bug_present(struct parport *pb)
>> +{
>> + struct cpuinfo_x86 *c = &cpu_data(0);
>> +
>> + if (c->x86_vendor == X86_VENDOR_INTEL && (c->x86 == 4 || c->x86 == 5))
>> + return intel_bug_present_check_epp(pb);
>
> You can have a non-Intel CPU in a 486 or Pentium board.
>
>> + return 0;
>> +}
>> +#else
>> +static int intel_bug_present(struct parport *pb)
>> +{
>> + return 0;
>> +}
>> +#endif
>>
>> static int parport_ECPPS2_supported(struct parport *pb)
>> {
>
>
>
> --
> Ondrej Zary
--
With best regards,
Matwey V. Kornilov.
Sternberg Astronomical Institute, Lomonosov Moscow State University, Russia
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