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 494F113AC4 for ; Mon, 26 Jun 2023 18:29:58 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B96E8C433C8; Mon, 26 Jun 2023 18:29:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1687804198; bh=VJwSSW7VUjSIMxSRaaQ2XZoVmSOxinwNm4f1SFdGTQE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pEpqm71ECciZfAEcpJB1w+JhOPjzAcm9RmdLjX451rFb72idbUGbKBMJE25GHtuSL KdEZybaOQZLhSDhVydxTRJn2JVo7q9zoIEELRasJs8qyujMa5305jwqP0aZggkuqGt wNMWTIlOA1Gygu1FkuFUyCcCVgfR+xRZlzEs4fr8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Matthew Gerlach , Russ Weight , Mark Brown , Sasha Levin Subject: [PATCH 6.1 074/170] regmap: spi-avmm: Fix regmap_bus max_raw_write Date: Mon, 26 Jun 2023 20:10:43 +0200 Message-ID: <20230626180803.957537454@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230626180800.476539630@linuxfoundation.org> References: <20230626180800.476539630@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Russ Weight [ Upstream commit c8e796895e2310b6130e7577248da1d771431a77 ] The max_raw_write member of the regmap_spi_avmm_bus structure is defined as: .max_raw_write = SPI_AVMM_VAL_SIZE * MAX_WRITE_CNT SPI_AVMM_VAL_SIZE == 4 and MAX_WRITE_CNT == 1 so this results in a maximum write transfer size of 4 bytes which provides only enough space to transfer the address of the target register. It provides no space for the value to be transferred. This bug became an issue (divide-by-zero in _regmap_raw_write()) after the following was accepted into mainline: commit 3981514180c9 ("regmap: Account for register length when chunking") Change max_raw_write to include space (4 additional bytes) for both the register address and value: .max_raw_write = SPI_AVMM_REG_SIZE + SPI_AVMM_VAL_SIZE * MAX_WRITE_CNT Fixes: 7f9fb67358a2 ("regmap: add Intel SPI Slave to AVMM Bus Bridge support") Reviewed-by: Matthew Gerlach Signed-off-by: Russ Weight Link: https://lore.kernel.org/r/20230620202824.380313-1-russell.h.weight@intel.com Signed-off-by: Mark Brown Signed-off-by: Sasha Levin --- drivers/base/regmap/regmap-spi-avmm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/base/regmap/regmap-spi-avmm.c b/drivers/base/regmap/regmap-spi-avmm.c index 4c2b94b3e30be..6af692844c196 100644 --- a/drivers/base/regmap/regmap-spi-avmm.c +++ b/drivers/base/regmap/regmap-spi-avmm.c @@ -660,7 +660,7 @@ static const struct regmap_bus regmap_spi_avmm_bus = { .reg_format_endian_default = REGMAP_ENDIAN_NATIVE, .val_format_endian_default = REGMAP_ENDIAN_NATIVE, .max_raw_read = SPI_AVMM_VAL_SIZE * MAX_READ_CNT, - .max_raw_write = SPI_AVMM_VAL_SIZE * MAX_WRITE_CNT, + .max_raw_write = SPI_AVMM_REG_SIZE + SPI_AVMM_VAL_SIZE * MAX_WRITE_CNT, .free_context = spi_avmm_bridge_ctx_free, }; -- 2.39.2