ide: fix for ide_timing quantisation errors

From: Bartlomiej Zolnierkiewicz <[email protected]>
Subject: [PATCH v2] ide: fix for ide_timing quantisation errors

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

---
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
===================================================================
@@ -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);

From: Bartlomiej Zolnierkiewicz <[email protected]>
Date: Thu, 13 Oct 2011 15:16:03 +0200

I'm not applying patches that sync up the ATA layer with the IDE layer in ways like this unless the change is in response to a user reported bug.

We're way past the stage where we are making changes to the IDE layer based purely upon visual inspection. I want a real user bug report to back most if not all changes.

These two layers will get out of sync, and you're going to have to accept that. Please concentrate your efforts on the ATA layer if you want to make cleanups, simplifications, and fixes based upon code audits.