Message-ID: <4b5332e8-6eef-3a3a-0765-a7563bc745ad@nbd.name>
Date:   Thu, 2 Dec 2021 17:26:26 +0100
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Subject: Re: [PATCH v2] mt76: eeprom: tolerate corrected bit-flips
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To:     Daniel Golle <daniel@makrotopia.org>,
        linux-mediatek@lists.infradead.org, linux-wireless@vger.kernel.org
Cc:     Ryder Lee <ryder.lee@mediatek.com>,
        Lorenzo Bianconi <lorenzo@kernel.org>,
        Hauke Mehrtens <hauke@hauke-m.de>
References: <YZ/nv74JH/uQwpBt@makrotopia.org>
From:   Felix Fietkau <nbd@nbd.name>
In-Reply-To: <YZ/nv74JH/uQwpBt@makrotopia.org>
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Hi,

On 2021-11-25 20:45, Daniel Golle wrote:
> mtd_read() returns -EUCLEAN in case of corrected bit-flips.
> As data was read, don't error out in this case.
> 
> Signed-off-by: Daniel Golle <daniel@makrotopia.org>
> ---
> v2: fix wrong variable name
> 
>   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 2d58aa31db934..4a5d14473ddc4 100644
> --- a/drivers/net/wireless/mediatek/mt76/eeprom.c
> +++ b/drivers/net/wireless/mediatek/mt76/eeprom.c
> @@ -65,7 +65,7 @@ int mt76_get_of_eeprom(struct mt76_dev *dev, void *eep, int offset, int len)
>   	offset = be32_to_cpup(list);
>   	ret = mtd_read(mtd, offset, len, &retlen, eep);
>   	put_mtd_device(mtd);
> -	if (ret) {
> +	if (ret && !mtd_is_bitflip(ret)) {
unfortunately the patch is still incomplete. I will fold in the
following change to make it work:
---
--- a/drivers/net/wireless/mediatek/mt76/eeprom.c
+++ b/drivers/net/wireless/mediatek/mt76/eeprom.c
@@ -65,7 +65,9 @@ int mt76_get_of_eeprom(struct mt76_dev *dev, void *eep, int offset, int len)
  	offset = be32_to_cpup(list);
  	ret = mtd_read(mtd, offset, len, &retlen, eep);
  	put_mtd_device(mtd);
-	if (ret && !mtd_is_bitflip(ret)) {
+	if (mtd_is_bitflip(ret))
+		ret = 0;
+	if (ret) {
  		dev_err(dev->dev, "reading EEPROM from mtd %s failed: %i\n",
  			part, ret);
  		goto out_put_node;