From patchwork Fri Jan 12 00:40:36 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nathan Chancellor X-Patchwork-Id: 762344 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 0406510A15; Fri, 12 Jan 2024 00:40:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="LilUtoxj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 56467C433C7; Fri, 12 Jan 2024 00:40:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1705020049; bh=HwjbaJjrteKjt3TiJuiyZijGvloQtp4+JKX0Ij2rFrI=; h=From:Date:Subject:To:Cc:From; b=LilUtoxjJKW1ggthMbr6tUEN0wnO1Nqqz5hw9Yz7q0hFmCo69MJCWCMuRYRtp6/hX HC/RVdmGWHbWfjM5qLNH9SC9me9dx/AxHdf0cPtOdQoj+byfhvkDYJaQfV1SS3LLpq HEjpJq4q/x/emJ30pa8w9PjI9B4EuTZTOhRJoR70Tfbt/N5D1Gyg76rm9HF/1Kv7S1 8bmc34QjS+WRipAtjgEBbYaYXHSsiaLm5X3zGsDy3KEHqaeRT23jVrWPovJMNNoccO f5iX4nNGApTYPiGQUy31TP6W8DMMDtzrvxAhSTNPTriXAcWGFnmm3LvW0vM7LNjl6v JickBn/NkewAQ== From: Nathan Chancellor Date: Thu, 11 Jan 2024 17:40:36 -0700 Subject: [PATCH] media: mxl5xx: Move xpt structures off stack Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240111-dvb-mxl5xx-move-structs-off-stack-v1-1-ca4230e67c11@kernel.org> X-B4-Tracking: v=1; b=H4sIAIOKoGUC/x2NQQqDMBAAvyJ77kJ2UYR+pfSgcdMuVlOyGgLi3 w3eZi4zB5gkFYNnc0CSrKZxrUKPBvx3WD+COlUHdtw6IsIpj7iUX1cKLjEL2pZ2vxnGECoPfkY hpp5HkuAYauefJGi5H6/3eV5ihne/cwAAAA== To: mchehab@kernel.org Cc: ndesaulniers@google.com, morbo@google.com, justinstitt@google.com, linux-media@vger.kernel.org, llvm@lists.linux.dev, patches@lists.linux.dev, stable@vger.kernel.org, Nathan Chancellor X-Mailer: b4 0.13-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=5603; i=nathan@kernel.org; h=from:subject:message-id; bh=HwjbaJjrteKjt3TiJuiyZijGvloQtp4+JKX0Ij2rFrI=; b=owGbwMvMwCUmm602sfCA1DTG02pJDKkLuib2eyb6ynxj2Zyw6MkHJ4m41L3mLN06qhM+h+xZl ZFXHNHfUcrCIMbFICumyFL9WPW4oeGcs4w3Tk2CmcPKBDKEgYtTACay8wgjw/R210XM+nr7A/h1 Fk92ElywfdrTJAfnPdEmHdudP21qbGdkeFvwmfnNJC7JqOjCN1qtxSV7bx44nLqqz/JR3CnFcqu v/AA= X-Developer-Key: i=nathan@kernel.org; a=openpgp; fpr=2437CB76E544CB6AB3D9DFD399739260CB6CB716 When building for LoongArch with clang 18.0.0, the stack usage of probe() is larger than the allowed 2048 bytes: drivers/media/dvb-frontends/mxl5xx.c:1698:12: warning: stack frame size (2368) exceeds limit (2048) in 'probe' [-Wframe-larger-than] 1698 | static int probe(struct mxl *state, struct mxl5xx_cfg *cfg) | ^ 1 warning generated. This is the result of the linked LLVM commit, which changes how the arrays of structures in config_ts() get handled with CONFIG_INIT_STACK_ZERO and CONFIG_INIT_STACK_PATTERN, which causes the above warning in combination with inlining, as config_ts() gets inlined into probe(). This warning can be easily fixed by moving the array of structures off of the stackvia 'static const', which is a better location for these variables anyways because they are static data that is only ever read from, never modified, so allocating the stack space is wasteful. This drops the stack usage from 2368 bytes to 256 bytes with the same compiler and configuration. Cc: stable@vger.kernel.org Closes: https://github.com/ClangBuiltLinux/linux/issues/1977 Link: https://github.com/llvm/llvm-project/commit/afe8b93ffdfef5d8879e1894b9d7dda40dee2b8d Signed-off-by: Nathan Chancellor Reviewed-by: Miguel Ojeda Tested-by: Miguel Ojeda --- drivers/media/dvb-frontends/mxl5xx.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) --- base-commit: 02d4e62ae2452c83e4a3e279b8e4cb4dcbad4b31 change-id: 20240111-dvb-mxl5xx-move-structs-off-stack-e12172b1ef02 Best regards, diff --git a/drivers/media/dvb-frontends/mxl5xx.c b/drivers/media/dvb-frontends/mxl5xx.c index 4ebbcf05cc09..91e9c378397c 100644 --- a/drivers/media/dvb-frontends/mxl5xx.c +++ b/drivers/media/dvb-frontends/mxl5xx.c @@ -1381,57 +1381,57 @@ static int config_ts(struct mxl *state, enum MXL_HYDRA_DEMOD_ID_E demod_id, u32 nco_count_min = 0; u32 clk_type = 0; - struct MXL_REG_FIELD_T xpt_sync_polarity[MXL_HYDRA_DEMOD_MAX] = { + static const struct MXL_REG_FIELD_T xpt_sync_polarity[MXL_HYDRA_DEMOD_MAX] = { {0x90700010, 8, 1}, {0x90700010, 9, 1}, {0x90700010, 10, 1}, {0x90700010, 11, 1}, {0x90700010, 12, 1}, {0x90700010, 13, 1}, {0x90700010, 14, 1}, {0x90700010, 15, 1} }; - struct MXL_REG_FIELD_T xpt_clock_polarity[MXL_HYDRA_DEMOD_MAX] = { + static const struct MXL_REG_FIELD_T xpt_clock_polarity[MXL_HYDRA_DEMOD_MAX] = { {0x90700010, 16, 1}, {0x90700010, 17, 1}, {0x90700010, 18, 1}, {0x90700010, 19, 1}, {0x90700010, 20, 1}, {0x90700010, 21, 1}, {0x90700010, 22, 1}, {0x90700010, 23, 1} }; - struct MXL_REG_FIELD_T xpt_valid_polarity[MXL_HYDRA_DEMOD_MAX] = { + static const struct MXL_REG_FIELD_T xpt_valid_polarity[MXL_HYDRA_DEMOD_MAX] = { {0x90700014, 0, 1}, {0x90700014, 1, 1}, {0x90700014, 2, 1}, {0x90700014, 3, 1}, {0x90700014, 4, 1}, {0x90700014, 5, 1}, {0x90700014, 6, 1}, {0x90700014, 7, 1} }; - struct MXL_REG_FIELD_T xpt_ts_clock_phase[MXL_HYDRA_DEMOD_MAX] = { + static const struct MXL_REG_FIELD_T xpt_ts_clock_phase[MXL_HYDRA_DEMOD_MAX] = { {0x90700018, 0, 3}, {0x90700018, 4, 3}, {0x90700018, 8, 3}, {0x90700018, 12, 3}, {0x90700018, 16, 3}, {0x90700018, 20, 3}, {0x90700018, 24, 3}, {0x90700018, 28, 3} }; - struct MXL_REG_FIELD_T xpt_lsb_first[MXL_HYDRA_DEMOD_MAX] = { + static const struct MXL_REG_FIELD_T xpt_lsb_first[MXL_HYDRA_DEMOD_MAX] = { {0x9070000C, 16, 1}, {0x9070000C, 17, 1}, {0x9070000C, 18, 1}, {0x9070000C, 19, 1}, {0x9070000C, 20, 1}, {0x9070000C, 21, 1}, {0x9070000C, 22, 1}, {0x9070000C, 23, 1} }; - struct MXL_REG_FIELD_T xpt_sync_byte[MXL_HYDRA_DEMOD_MAX] = { + static const struct MXL_REG_FIELD_T xpt_sync_byte[MXL_HYDRA_DEMOD_MAX] = { {0x90700010, 0, 1}, {0x90700010, 1, 1}, {0x90700010, 2, 1}, {0x90700010, 3, 1}, {0x90700010, 4, 1}, {0x90700010, 5, 1}, {0x90700010, 6, 1}, {0x90700010, 7, 1} }; - struct MXL_REG_FIELD_T xpt_enable_output[MXL_HYDRA_DEMOD_MAX] = { + static const struct MXL_REG_FIELD_T xpt_enable_output[MXL_HYDRA_DEMOD_MAX] = { {0x9070000C, 0, 1}, {0x9070000C, 1, 1}, {0x9070000C, 2, 1}, {0x9070000C, 3, 1}, {0x9070000C, 4, 1}, {0x9070000C, 5, 1}, {0x9070000C, 6, 1}, {0x9070000C, 7, 1} }; - struct MXL_REG_FIELD_T xpt_err_replace_sync[MXL_HYDRA_DEMOD_MAX] = { + static const struct MXL_REG_FIELD_T xpt_err_replace_sync[MXL_HYDRA_DEMOD_MAX] = { {0x9070000C, 24, 1}, {0x9070000C, 25, 1}, {0x9070000C, 26, 1}, {0x9070000C, 27, 1}, {0x9070000C, 28, 1}, {0x9070000C, 29, 1}, {0x9070000C, 30, 1}, {0x9070000C, 31, 1} }; - struct MXL_REG_FIELD_T xpt_err_replace_valid[MXL_HYDRA_DEMOD_MAX] = { + static const struct MXL_REG_FIELD_T xpt_err_replace_valid[MXL_HYDRA_DEMOD_MAX] = { {0x90700014, 8, 1}, {0x90700014, 9, 1}, {0x90700014, 10, 1}, {0x90700014, 11, 1}, {0x90700014, 12, 1}, {0x90700014, 13, 1}, {0x90700014, 14, 1}, {0x90700014, 15, 1} }; - struct MXL_REG_FIELD_T xpt_continuous_clock[MXL_HYDRA_DEMOD_MAX] = { + static const struct MXL_REG_FIELD_T xpt_continuous_clock[MXL_HYDRA_DEMOD_MAX] = { {0x907001D4, 0, 1}, {0x907001D4, 1, 1}, {0x907001D4, 2, 1}, {0x907001D4, 3, 1}, {0x907001D4, 4, 1}, {0x907001D4, 5, 1}, {0x907001D4, 6, 1}, {0x907001D4, 7, 1} }; - struct MXL_REG_FIELD_T xpt_nco_clock_rate[MXL_HYDRA_DEMOD_MAX] = { + static const struct MXL_REG_FIELD_T xpt_nco_clock_rate[MXL_HYDRA_DEMOD_MAX] = { {0x90700044, 16, 80}, {0x90700044, 16, 81}, {0x90700044, 16, 82}, {0x90700044, 16, 83}, {0x90700044, 16, 84}, {0x90700044, 16, 85},