From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7FFCA42189E for ; Fri, 8 May 2026 19:32:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778268729; cv=none; b=Jk2D9DYWmwGeNkuKlb7aLYVkg34IaJftkbwdDUb+SkQaUigL8fozbqwwfo/gYXc0Ru1x3wB2/RMqkLmBAShg1d7kE2djV47tqLlhN47E1gVPzs3WS2b/69O0wqcPaduoSUNiXFcif5rsjWml7gBC8vmqM/sg0f3ZaYKLcVwnpUY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778268729; c=relaxed/simple; bh=M+ftPlcwkvWORrTRE+nqgDJgBpR6sZdPBpMXtRlnNGg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=F/uWq3Z9/4s/vphhlzoIEL6g7S8RN+TgzhvTgf0KBPnbn/7sUUEWjY+PY/CPoL1T1jBKoqizOaeCS2hNUQ+rhKmVV/NR289nAZXAcB2Tgmgs4YFcXwdF8nlhLoXce0ZRUNyM95dVjr8wNV0X/UTOthKRtGGQX9KO7lkUIpKG9gc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=O8RVJcEj; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="O8RVJcEj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C2FB2C2BCF4; Fri, 8 May 2026 19:32:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778268729; bh=M+ftPlcwkvWORrTRE+nqgDJgBpR6sZdPBpMXtRlnNGg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=O8RVJcEjMVGTo/86m/SpFPeC2iIfWIIhLui1IIiHUIDXsV6fmJTmcvn0ZbzFGrC7s ET4DsnSPnpq07vLCzry1FVniprlGqQF41b9CpKK4L4FOr53X/nlnchuNBMKGi2pozo gZSF9ITxCva4yOFCaZ61J/ARm1jymH+8/sze2PcF1MP3BAttYAc9T5GSVra5G7Splk SoHBYPL+vzh8LPVsMAZcyXUys05MsR4nM/h3lN5o9DVTnQtAaS/qLnA53DU/quXzpK UyOO1yWMkemDJvntUWMkQld3hp+u3T8tMOCJp/bhJ2T1sMtT+hFrqO6h+Ivk+6+vj3 7XzAlC6BvKp1Q== From: Sasha Levin To: stable@vger.kernel.org Cc: Sanjaikumar V S , Hendrik Donner , "Pratyush Yadav (Google)" , Sasha Levin Subject: [PATCH 6.1.y 2/2] mtd: spi-nor: sst: Fix write enable before AAI sequence Date: Fri, 8 May 2026 15:32:04 -0400 Message-ID: <20260508193205.1850313-2-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260508193205.1850313-1-sashal@kernel.org> References: <2026050405-sizzling-activate-5c93@gregkh> <20260508193205.1850313-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Sanjaikumar V S [ Upstream commit a0f64241d3566a49c0a9b33ba7ae458ae22003a9 ] When writing to SST flash starting at an odd address, a single byte is first programmed using the byte program (BP) command. After this operation completes, the flash hardware automatically clears the Write Enable Latch (WEL) bit. If an AAI (Auto Address Increment) word program sequence follows, it requires WEL to be set. Without re-enabling writes, the AAI sequence fails. Add spi_nor_write_enable() after the odd-address byte program when more data needs to be written. Use a local boolean for clarity. Fixes: b199489d37b2 ("mtd: spi-nor: add the framework for SPI NOR") Cc: stable@vger.kernel.org Signed-off-by: Sanjaikumar V S Tested-by: Hendrik Donner Reviewed-by: Hendrik Donner Signed-off-by: Pratyush Yadav (Google) Signed-off-by: Sasha Levin --- drivers/mtd/spi-nor/sst.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/mtd/spi-nor/sst.c b/drivers/mtd/spi-nor/sst.c index 8b705ff66615d..75d152a959a91 100644 --- a/drivers/mtd/spi-nor/sst.c +++ b/drivers/mtd/spi-nor/sst.c @@ -153,6 +153,8 @@ static int sst_nor_write(struct mtd_info *mtd, loff_t to, size_t len, /* Start write from odd address. */ if (to % 2) { + bool needs_write_enable = (len > 1); + /* write one byte. */ ret = sst_nor_write_data(nor, to, 1, buf); if (ret < 0) @@ -160,6 +162,17 @@ static int sst_nor_write(struct mtd_info *mtd, loff_t to, size_t len, to++; actual++; + + /* + * Byte program clears the write enable latch. If more + * data needs to be written using the AAI sequence, + * re-enable writes. + */ + if (needs_write_enable) { + ret = spi_nor_write_enable(nor); + if (ret) + goto out; + } } /* Write out most of the data here. */ -- 2.53.0