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 8819A20B05 for ; Wed, 4 Oct 2023 18:31:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="JtAU6bkE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 09FAAC433C7; Wed, 4 Oct 2023 18:31:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1696444312; bh=esN8fUUbC54lkQPgLbr4o42r6UR05R32m+4o9vJ98ZM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JtAU6bkEJjadYtDz1ayajWFZXnat9fNditfqhf6WFbDvH15sfq82dCwfYo30Q2JuL UN0klQxGKGAOkP9hWUwiHtrnqeBYtlapVm9TIMhm2Oe7r4CdRmKx/jzKILWMM3Pwr2 H5KmbSmxQ+tcJ2j840BOYUB6S1V9C9sETcAFGLrM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Valentin Caron , Mark Brown , Sasha Levin Subject: [PATCH 6.5 205/321] spi: stm32: add a delay before SPI disable Date: Wed, 4 Oct 2023 19:55:50 +0200 Message-ID: <20231004175238.747534651@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231004175229.211487444@linuxfoundation.org> References: <20231004175229.211487444@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Valentin Caron [ Upstream commit 6de8a70c84ee0586fdde4e671626b9caca6aed74 ] As explained in errata sheet, in section "2.14.5 Truncation of SPI output signals after EOT event": On STM32MP1x, EOT interrupt can be thrown before the true end of communication. So we add a delay of a half period to wait the real end of the transmission. Link: https://www.st.com/resource/en/errata_sheet/es0539-stm32mp131x3x5x-device-errata-stmicroelectronics.pdf Signed-off-by: Valentin Caron Link: https://lore.kernel.org/r/20230906132735.748174-1-valentin.caron@foss.st.com Signed-off-by: Mark Brown Signed-off-by: Sasha Levin --- drivers/spi/spi-stm32.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c index 7ddf9db776b06..4737a36e5d4e9 100644 --- a/drivers/spi/spi-stm32.c +++ b/drivers/spi/spi-stm32.c @@ -275,6 +275,7 @@ struct stm32_spi_cfg { * @fifo_size: size of the embedded fifo in bytes * @cur_midi: master inter-data idleness in ns * @cur_speed: speed configured in Hz + * @cur_half_period: time of a half bit in us * @cur_bpw: number of bits in a single SPI data frame * @cur_fthlv: fifo threshold level (data frames in a single data packet) * @cur_comm: SPI communication mode @@ -302,6 +303,7 @@ struct stm32_spi { unsigned int cur_midi; unsigned int cur_speed; + unsigned int cur_half_period; unsigned int cur_bpw; unsigned int cur_fthlv; unsigned int cur_comm; @@ -466,6 +468,8 @@ static int stm32_spi_prepare_mbr(struct stm32_spi *spi, u32 speed_hz, spi->cur_speed = spi->clk_rate / (1 << mbrdiv); + spi->cur_half_period = DIV_ROUND_CLOSEST(USEC_PER_SEC, 2 * spi->cur_speed); + return mbrdiv - 1; } @@ -707,6 +711,10 @@ static void stm32h7_spi_disable(struct stm32_spi *spi) return; } + /* Add a delay to make sure that transmission is ended. */ + if (spi->cur_half_period) + udelay(spi->cur_half_period); + if (spi->cur_usedma && spi->dma_tx) dmaengine_terminate_async(spi->dma_tx); if (spi->cur_usedma && spi->dma_rx) -- 2.40.1