[net-next RFC PATCH 1/6] wifi: mt76: fix broken precal loading from MTD for mt7915

[net-next RFC PATCH 1/6] wifi: mt76: fix broken precal loading from MTD for mt7915

[Christian Marangi]

Commit 495184ac91bb ("mt76: mt7915: add support for applying
pre-calibration data") was fundamentally broken and never worked.

The idea (before NVMEM support) was to expand the MTD function and pass
an additional offset. For normal EEPROM load the offset would always be
0. For the purpose of precal loading, an offset was passed that was
internally the size of EEPROM, since precal data is right after the
EEPROM.

Problem is that the offset value passed is never handled and is actually
overwrite by

	offset = be32_to_cpup(list);
	ret = mtd_read(mtd, offset, len, &retlen, eep);

resulting in the passed offset value always ingnored. (and even passing
garbage data as precal as the start of the EEPROM is getting read)

Fix this by adding to the current offset value, the offset from DT to
correctly read the piece of data at the requested location.

Cc: stable@vger.kernel.org
Fixes: 495184ac91bb ("mt76: mt7915: add support for applying pre-calibration data")
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
---
 drivers/net/wireless/mediatek/mt76/eeprom.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/mediatek/mt76/eeprom.c b/drivers/net/wireless/mediatek/mt76/eeprom.c
index 36564930aef1..2558788f7ffb 100644
--- a/drivers/net/wireless/mediatek/mt76/eeprom.c
+++ b/drivers/net/wireless/mediatek/mt76/eeprom.c
@@ -67,7 +67,7 @@ static int mt76_get_of_epprom_from_mtd(struct mt76_dev *dev, void *eep, int offs
 		goto out_put_node;
 	}
 
-	offset = be32_to_cpup(list);
+	offset += be32_to_cpup(list);
 	ret = mtd_read(mtd, offset, len, &retlen, eep);
 	put_mtd_device(mtd);
 	if (mtd_is_bitflip(ret))
-- 
2.40.1

Re: [net-next RFC PATCH 1/6] wifi: mt76: fix broken precal loading from MTD for mt7915

[Kalle Valo]

Christian Marangi <ansuelsmth@gmail.com> writes:

> Commit 495184ac91bb ("mt76: mt7915: add support for applying
> pre-calibration data") was fundamentally broken and never worked.
>
> The idea (before NVMEM support) was to expand the MTD function and pass
> an additional offset. For normal EEPROM load the offset would always be
> 0. For the purpose of precal loading, an offset was passed that was
> internally the size of EEPROM, since precal data is right after the
> EEPROM.
>
> Problem is that the offset value passed is never handled and is actually
> overwrite by
>
> 	offset = be32_to_cpup(list);
> 	ret = mtd_read(mtd, offset, len, &retlen, eep);
>
> resulting in the passed offset value always ingnored. (and even passing
> garbage data as precal as the start of the EEPROM is getting read)
>
> Fix this by adding to the current offset value, the offset from DT to
> correctly read the piece of data at the requested location.
>
> Cc: stable@vger.kernel.org
> Fixes: 495184ac91bb ("mt76: mt7915: add support for applying pre-calibration data")
> Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>

mt76 patches go to Felix's tree, not net-next.

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