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);
+ return 0;
+}
+#else
+static int intel_bug_present(struct parport *pb)
+{
+ return 0;
+}
+#endif
static int parport_ECPPS2_supported(struct parport *pb)
{
--
1.8.1.4
--
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