From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 D0AEE3E3D98 for ; Thu, 25 Jun 2026 12:52:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782391929; cv=none; b=tdA6WwFaO9PA6XAI1R82xxlz4Ge2H23tJ4CMt26I7Ulc/+d4FMLQbuc30fjBUZESXwBR9ngjz8F6FisPKZHo4EvkViSoUaRY76Ldr/8LIDjB4BHEWBk2VQrYxCda6m9MMLqJD4ZujjNfmXl0tU7u6IpNrLUcYAot2jlL6ifnHtU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782391929; c=relaxed/simple; bh=hdPX9sU0ppmNFLDsSnbrWlN73uQ/YB1jvYe5lO32hSI=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=VL7TVyARNBywA7fwgl9kpjQe7LPi+Eg06jBEKLzL64Qze+ojUqUoTVIIBijJmWio5sB1UOZSOoevdMgnd39uWFxS6gHCilDJPjtpUxuC1fr4NqmA6e8T/j0FOhre92oSm91zy7uWNX9thvMzzjYWplVJ69PQETXOhTwOuaDRQHk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=HvHBtah4; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="HvHBtah4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F30E61F000E9; Thu, 25 Jun 2026 12:52:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1782391928; bh=3La/XFBxb4xyYmyJ4Xdp0O0lRSob30WDyJkXZZDm6gs=; h=Subject:To:Cc:From:Date; b=HvHBtah4zg08Ww3G/Y/3V+35hU1VGDPCxf47VL5cBIUbJ5KXJP6nChTuyek+FjbzR rgPxF9WAkOR1QtZMIlIj5/Z142ik+uKXjfxNTFiU9Ye9JlaOgO+BIWXaucnc7Lce7M dAnKgZ6KUcwVMurqrdtsg5AOThVrJBy6Wxhlz5+g= Subject: FAILED: patch "[PATCH] serial: qcom_geni: Fix RX DMA stall when SE_DMA_RX_LEN_IN is" failed to apply to 6.6-stable tree To: viken.dadhaniya@oss.qualcomm.com,bartosz.golaszewski@oss.qualcomm.com,gregkh@linuxfoundation.org Cc: From: Date: Thu, 25 Jun 2026 13:46:23 +0100 Message-ID: <2026062523-sulfite-banking-76d6@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x b93062b6d8a1b2d9bad235cac25558a909819026 # git commit -s git send-email --to '' --in-reply-to '2026062523-sulfite-banking-76d6@gregkh' --subject-prefix 'PATCH 6.6.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From b93062b6d8a1b2d9bad235cac25558a909819026 Mon Sep 17 00:00:00 2001 From: Viken Dadhaniya Date: Thu, 28 May 2026 22:48:07 +0530 Subject: [PATCH] serial: qcom_geni: Fix RX DMA stall when SE_DMA_RX_LEN_IN is zero In qcom_geni_serial_handle_rx_dma(), geni_se_rx_dma_unprep() clears port->rx_dma_addr before SE_DMA_RX_LEN_IN is read. If the register is zero, for example when the RX stale counter fires on an idle line, the handler returns without calling geni_se_rx_dma_prep(). The next RX DMA interrupt then hits the !port->rx_dma_addr guard and returns immediately, so the RX DMA buffer is never rearmed and later input is lost. Keep the handler on the rearm path when rx_in is zero. Warn about the unexpected zero-length DMA completion, skip received-data handling, and always call geni_se_rx_dma_prep(). Fixes: 2aaa43c70778 ("tty: serial: qcom-geni-serial: add support for serial engine DMA") Cc: stable@vger.kernel.org Reviewed-by: Bartosz Golaszewski Signed-off-by: Viken Dadhaniya Link: https://patch.msgid.link/20260528-serial-rx-0-byte-fix-v2-1-b4195cfe342f@oss.qualcomm.com Signed-off-by: Greg Kroah-Hartman diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c index d81b539cff7f..7ead87b4eb65 100644 --- a/drivers/tty/serial/qcom_geni_serial.c +++ b/drivers/tty/serial/qcom_geni_serial.c @@ -905,12 +905,9 @@ static void qcom_geni_serial_handle_rx_dma(struct uart_port *uport, bool drop) port->rx_dma_addr = 0; rx_in = readl(uport->membase + SE_DMA_RX_LEN_IN); - if (!rx_in) { - dev_warn(uport->dev, "serial engine reports 0 RX bytes in!\n"); - return; - } - - if (!drop) + if (!rx_in) + dev_warn_ratelimited(uport->dev, "serial engine reports 0 RX bytes in!\n"); + else if (!drop) handle_rx_uart(uport, rx_in); ret = geni_se_rx_dma_prep(&port->se, port->rx_buf,