[PATCH v2] ide: fix for ide_timing quantisation errors

From: Bartlomiej Zolnierkiewicz
Date: Thu Oct 13 2011 - 09:20:58 EST


From: Bartlomiej Zolnierkiewicz <bzolnier@xxxxxxxxx>
Subject: [PATCH v2] ide: fix for ide_timing quantisation errors

Based on commit 4f701d1 ("ata_timing: ensure t->cycle is always
correct") for libata.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@xxxxxxxxx>
---
v2: fixed comment style

earlier references:
https://lkml.org/lkml/2010/1/18/274

drivers/ide/ide-timings.c | 8 ++++++++
1 file changed, 8 insertions(+)

Index: b/drivers/ide/ide-timings.c
===================================================================
--- a/drivers/ide/ide-timings.c
+++ b/drivers/ide/ide-timings.c
@@ -206,6 +206,14 @@ int ide_timing_compute(ide_drive_t *driv
t->recover = t->cycle - t->active;
}

+ /*
+ * In a few cases quantisation may produce enough errors to
+ * leave t->cycle too low for the sum of active and recovery
+ * if so we must correct this
+ */
+ if (t->active + t->recover > t->cycle)
+ t->cycle = t->active + t->recover;
+
return 0;
}
EXPORT_SYMBOL_GPL(ide_timing_compute);
--
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