[PATCH] Fix resume on x86-32 machines

From: Pavel Machek
Date: Sun Dec 10 2017 - 16:38:17 EST



After 4.15-rc2, suspend stopped working on Thinkpad X60. 5b06bbc
(unintentionally?) reordered stuff with respect to
fix_processor_context() on 32-bit and 64-bit. We undo that change on
32-bit.

While we are at it, fix a comment.

Signed-off-by: Pavel Machek <pavel@xxxxxx>
Fixes: 5b06bbcfc2c621da3009da8decb7511500c293ed

diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c
index 5191de1..af7b613 100644
--- a/arch/x86/power/cpu.c
+++ b/arch/x86/power/cpu.c
@@ -216,8 +216,8 @@ static void notrace __restore_processor_state(struct saved_context *ctxt)
write_cr0(ctxt->cr0);

/*
- * now restore the descriptor tables to their proper values
- * ltr is done i fix_processor_context().
+ * Now restore the descriptor tables to their proper values
+ * ltr is done in fix_processor_context().
*/
#ifdef CONFIG_X86_32
load_idt(&ctxt->idt);
@@ -235,13 +235,11 @@ static void notrace __restore_processor_state(struct saved_context *ctxt)
wrmsrl(MSR_GS_BASE, ctxt->gs_base);
#endif

- fix_processor_context();
-
+#ifdef CONFIG_X86_32
/*
- * Restore segment registers. This happens after restoring the GDT
- * and LDT, which happen in fix_processor_context().
+ * Restore segment registers.
*/
-#ifdef CONFIG_X86_32
+
loadsegment(es, ctxt->es);
loadsegment(fs, ctxt->fs);
loadsegment(gs, ctxt->gs);
@@ -252,8 +250,17 @@ static void notrace __restore_processor_state(struct saved_context *ctxt)
*/
if (boot_cpu_has(X86_FEATURE_SEP))
enable_sep_cpu();
+
+ fix_processor_context();
#else
/* CONFIG_X86_64 */
+ /*
+ * Restore segment registers. This happens after restoring the GDT
+ * and LDT, which happen in fix_processor_context().
+ */
+
+ fix_processor_context();
+
asm volatile ("movw %0, %%ds" :: "r" (ctxt->ds));
asm volatile ("movw %0, %%es" :: "r" (ctxt->es));
asm volatile ("movw %0, %%fs" :: "r" (ctxt->fs));


--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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