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 A5EDF52F72; Mon, 11 Dec 2023 18:35:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="BkeSh9uu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 29C12C433CB; Mon, 11 Dec 2023 18:35:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1702319756; bh=8emQgtLLFpahAm3MzJYenwFV+xPzAlif6M9QykqcHUQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BkeSh9uuLpZ4quJ5hkIsG+5IBaLXDq2OrIFa24wQvV9x4XNjHHko7GfljnHQFQxVa U8Rlqkf+NbkWf9K7BEPfaHnUedQfNjmY9ukniGG5JJkui/HLECDoS5m/nTxqeEw8ga zsvO8zy5OtPXjtgya1PQgWqZaPZW46bHrWyiykpM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ronald Wahl , Vignesh Raghavendra Subject: [PATCH 6.6 222/244] serial: 8250: 8250_omap: Do not start RX DMA on THRI interrupt Date: Mon, 11 Dec 2023 19:21:55 +0100 Message-ID: <20231211182055.949325881@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20231211182045.784881756@linuxfoundation.org> References: <20231211182045.784881756@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ronald Wahl commit c6bb057418876cdfdd29a6f7b8cef54539ee8811 upstream. Starting RX DMA on THRI interrupt is too early because TX may not have finished yet. This change is inspired by commit 90b8596ac460 ("serial: 8250: Prevent starting up DMA Rx on THRI interrupt") and fixes DMA issues I had with an AM62 SoC that is using the 8250 OMAP variant. Cc: stable@vger.kernel.org Fixes: c26389f998a8 ("serial: 8250: 8250_omap: Add DMA support for UARTs on K3 SoCs") Signed-off-by: Ronald Wahl Reviewed-by: Vignesh Raghavendra Link: https://lore.kernel.org/r/20231101171431.16495-1-rwahl@gmx.de Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_omap.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) --- a/drivers/tty/serial/8250/8250_omap.c +++ b/drivers/tty/serial/8250/8250_omap.c @@ -1282,10 +1282,12 @@ static int omap_8250_dma_handle_irq(stru status = serial_port_in(port, UART_LSR); - if (priv->habit & UART_HAS_EFR2) - am654_8250_handle_rx_dma(up, iir, status); - else - status = omap_8250_handle_rx_dma(up, iir, status); + if ((iir & 0x3f) != UART_IIR_THRI) { + if (priv->habit & UART_HAS_EFR2) + am654_8250_handle_rx_dma(up, iir, status); + else + status = omap_8250_handle_rx_dma(up, iir, status); + } serial8250_modem_status(up); if (status & UART_LSR_THRE && up->dma->tx_err) {