commit a258f183ee4e48e9352b408e8448467eebdc6cd2

commit a258f183ee4e48e9352b408e8448467eebdc6cd2

[Tejun Heo]

Happy new year, Jeff, Alan.

I'm curious why commit a258f183 got in?  We already deal with this
problem by executing SETXFER by polling.  That's better IMHO for two
reasons - no clutter in hot path && applies to drivers which use custom
interrupt handlers.

Thanks.

-- 
tejun

Re: commit a258f183ee4e48e9352b408e8448467eebdc6cd2

[Alan Cox]

On Wed, 02 Jan 2008 18:34:38 +0900
Tejun Heo <htejun@gmail.com> wrote:

> Happy new year, Jeff, Alan.
> 
> I'm curious why commit a258f183 got in?  

Whats that commit in real code ?

Re: commit a258f183ee4e48e9352b408e8448467eebdc6cd2

[Tejun Heo]

[-- Attachment #1: Type: text/plain, Size: 241 bytes --]

Alan Cox wrote:
> On Wed, 02 Jan 2008 18:34:38 +0900
> Tejun Heo <htejun@gmail.com> wrote:
> 
>> Happy new year, Jeff, Alan.
>>
>> I'm curious why commit a258f183 got in?  
> 
> Whats that commit in real code ?

The attached one.

-- 
tejun

[-- Attachment #2: 0001-libata-fix-hopefully-all-the-remaining-problems-w.patch --]
[-- Type: text/x-patch, Size: 2062 bytes --]

>From a258f183ee4e48e9352b408e8448467eebdc6cd2 Mon Sep 17 00:00:00 2001
From: Alan <alan@lxorguk.ukuu.org.uk>
Date: Tue, 2 Oct 2007 13:53:05 -0700
Subject: [PATCH] libata: fix (hopefully) all the remaining problems with devices failing setup/identify

Two fixes in this test patch.  One of them allows old CF cards to refuse
pio mode setting, and one to wait for the drive to settle after a set
features changes the speed settings, which is based upon the workarounds
used by drivers/ide.

Please test and report back if you have an afflicted system.  This patch
isn't for merging just testing.

The CF card fix will still display errors when the card works (got fixes
for that once I know the cure works) but should then be found/usable.

Not signed off by anyone, not for merging

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 drivers/ata/libata-core.c |   15 +++++++++++++++
 1 files changed, 15 insertions(+), 0 deletions(-)

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 0c2f37e..2b24041 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -6134,6 +6134,7 @@ inline unsigned int ata_host_intr(struct ata_port *ap,
 {
 	struct ata_eh_info *ehi = &ap->link.eh_info;
 	u8 status, host_stat = 0;
+	int i;
 
 	VPRINTK("ata%u: protocol %d task_state %d\n",
 		ap->print_id, qc->tf.protocol, ap->hsm_task_state);
@@ -6190,6 +6191,20 @@ inline unsigned int ata_host_intr(struct ata_port *ap,
 	if (unlikely(status & ATA_BUSY))
 		goto idle_irq;
 
+	if (unlikely(qc->tf.command == ATA_CMD_SET_FEATURES &&
+			qc->tf.feature == SETFEATURES_XFER)) {
+		/* Let the timings change settle and the drive catch up as
+		   some hardware needs up to 10uS to get its brain back in
+		   gear. Taken from the workarounds in drivers/ide done by
+		   Matthew Faupel/Niccolo Rigacci */
+		for (i = 0; i < 10; i++) {
+			if ((status & (ATA_BUSY | ATA_DRQ | ATA_ERR)) == 0)
+				break;
+			udelay(1);
+			status = ata_chk_status(ap);
+		}
+	}
+
 	/* ack bmdma irq events */
 	ap->ops->irq_clear(ap);
 
-- 
1.5.2.4

Re: commit a258f183ee4e48e9352b408e8448467eebdc6cd2

[Alan Cox]

On Wed, 02 Jan 2008 23:24:30 +0900
Tejun Heo <htejun@gmail.com> wrote:

> Alan Cox wrote:
> > On Wed, 02 Jan 2008 18:34:38 +0900
> > Tejun Heo <htejun@gmail.com> wrote:
> > 
> >> Happy new year, Jeff, Alan.
> >>
> >> I'm curious why commit a258f183 got in?  
> > 
> > Whats that commit in real code ?
> 
> The attached one.

Ok I don't see how that is related to the switch to polling. The
old IDE code found it neccessary and always did polling.

Alan

Re: commit a258f183ee4e48e9352b408e8448467eebdc6cd2

[Tejun Heo]

Alan Cox wrote:
> On Wed, 02 Jan 2008 23:24:30 +0900
> Tejun Heo <htejun@gmail.com> wrote:
> 
>> Alan Cox wrote:
>>> On Wed, 02 Jan 2008 18:34:38 +0900
>>> Tejun Heo <htejun@gmail.com> wrote:
>>>
>>>> Happy new year, Jeff, Alan.
>>>>
>>>> I'm curious why commit a258f183 got in?  
>>> Whats that commit in real code ?
>> The attached one.
> 
> Ok I don't see how that is related to the switch to polling. The
> old IDE code found it neccessary and always did polling.

ata_host_intr() is just never traveled while executing SETXFER because
SETXFERs are executed using polling which nicely works around quirky
controllers which raises interrupt a tad bit too early during SETXFER.

-- 
tejun

Re: commit a258f183ee4e48e9352b408e8448467eebdc6cd2

[Alan Cox]

> ata_host_intr() is just never traveled while executing SETXFER because
> SETXFERs are executed using polling which nicely works around quirky
> controllers which raises interrupt a tad bit too early during SETXFER.

Ok

Re: commit a258f183ee4e48e9352b408e8448467eebdc6cd2

[Tejun Heo]

Alan Cox wrote:
>> ata_host_intr() is just never traveled while executing SETXFER because
>> SETXFERs are executed using polling which nicely works around quirky
>> controllers which raises interrupt a tad bit too early during SETXFER.
> 
> Ok

Okay.  Jeff, can you please revert the commit?  Thanks.

-- 
tejun