From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from fllv0016.ext.ti.com (fllv0016.ext.ti.com [198.47.19.142]) (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 EDFBB393; Fri, 14 Jun 2024 06:13:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.47.19.142 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718345639; cv=none; b=BOK/hYqCMJYVIipK0QkUIinfGo82+hWn1XLEx043TYQQiWHAv3vb2pM7nAtn699Y0T2P9HwKTu8U2OFOs2XhLoFnNZi2jLbFzWqS1kPMLNTz9SEWzu1Csu0JsRdCCmkkR2y3fhNQRFsI/BZXSidBC0uDw0c/W9U3dpLiOVHXFUk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718345639; c=relaxed/simple; bh=dINWXejZejeNvy4vTa+5QjhOC1IhShPhljwOH1oq2kE=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=unY9lpca9K3NTWBGlRo0M5KDyEFcCwV7P6MS9jKrdl19ngAdvfQ4ytXCfUh0KLyJIOfQK9h8zXERhG/yyEkBmhlWMtCSQExhJm6aHyQ5sW8Uw8TzSO6iNbbLf3+CaPd5nCJ2bUmAjzkZFb+1R6pmIVUiLtw8MRpBg9JDll2Na2Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=ti.com; spf=pass smtp.mailfrom=ti.com; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b=oPG9e+KI; arc=none smtp.client-ip=198.47.19.142 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=ti.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ti.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="oPG9e+KI" Received: from lelv0265.itg.ti.com ([10.180.67.224]) by fllv0016.ext.ti.com (8.15.2/8.15.2) with ESMTP id 45E6DWOZ027648; Fri, 14 Jun 2024 01:13:32 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1718345612; bh=nwOhQ5GEl1mes6kpUbvK009JH5lDGyw8RkwUP7+kb+U=; h=From:To:CC:Subject:Date; b=oPG9e+KIT8W/VpjXOcin87RH8gqO4PLdcuiaa5xRrxRodtTxI7iaLvGl4LsRwWCac nqIxdpeDwh/QexbOE0H8ywd64ILOGVK/SArXHeta09qQod1ldUpBH/85X7q9xH+Cq/ pX04AWd6BmV42w7+hlbjiMw1AHtWrO8mIwvgsvys= Received: from DFLE107.ent.ti.com (dfle107.ent.ti.com [10.64.6.28]) by lelv0265.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 45E6DWhs021266 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 14 Jun 2024 01:13:32 -0500 Received: from DFLE105.ent.ti.com (10.64.6.26) by DFLE107.ent.ti.com (10.64.6.28) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23; Fri, 14 Jun 2024 01:13:32 -0500 Received: from lelvsmtp5.itg.ti.com (10.180.75.250) by DFLE105.ent.ti.com (10.64.6.26) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23 via Frontend Transport; Fri, 14 Jun 2024 01:13:32 -0500 Received: from udit-HP-Z2-Tower-G9-Workstation-Desktop-PC.dhcp.ti.com (udit-hp-z2-tower-g9-workstation-desktop-pc.dhcp.ti.com [172.24.227.18]) by lelvsmtp5.itg.ti.com (8.15.2/8.15.2) with ESMTP id 45E6DSuq026165; Fri, 14 Jun 2024 01:13:29 -0500 From: Udit Kumar To: , , CC: , , , , , , , , Udit Kumar Subject: [PATCH] serial: 8250_omap: Implementation of Errata i2310 Date: Fri, 14 Jun 2024 11:43:14 +0530 Message-ID: <20240614061314.290840-1-u-kumar1@ti.com> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 As per Errata i2310[0], Erroneous timeout can be triggered, if this Erroneous interrupt is not cleared then it may leads to strom of interrupts, therefore apply Errata i2310 solution. [0] https://www.ti.com/lit/pdf/sprz536 page 23 Signed-off-by: Udit Kumar --- drivers/tty/serial/8250/8250_omap.c | 25 ++++++++++++++++++++----- 1 file changed, 20 insertions(+), 5 deletions(-) diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c index 170639d12b2a..38eb639f78d3 100644 --- a/drivers/tty/serial/8250/8250_omap.c +++ b/drivers/tty/serial/8250/8250_omap.c @@ -115,6 +115,10 @@ /* RX FIFO occupancy indicator */ #define UART_OMAP_RX_LVL 0x19 +/* Timeout Low and High */ +#define UART_OMAP_TO_L 0x26 +#define UART_OMAP_TO_H 0x27 + /* * Copy of the genpd flags for the console. * Only used if console suspend is disabled @@ -663,13 +667,24 @@ static irqreturn_t omap8250_irq(int irq, void *dev_id) /* * On K3 SoCs, it is observed that RX TIMEOUT is signalled after - * FIFO has been drained, in which case a dummy read of RX FIFO - * is required to clear RX TIMEOUT condition. + * FIFO has been drained or erroneously. + * So apply solution of Errata i2310 as mentioned in + * https://www.ti.com/lit/pdf/sprz536 */ if (priv->habit & UART_RX_TIMEOUT_QUIRK && - (iir & UART_IIR_RX_TIMEOUT) == UART_IIR_RX_TIMEOUT && - serial_port_in(port, UART_OMAP_RX_LVL) == 0) { - serial_port_in(port, UART_RX); + (iir & UART_IIR_RX_TIMEOUT) == UART_IIR_RX_TIMEOUT) { + unsigned char efr2, timeout_h, timeout_l; + + efr2 = serial_in(up, UART_OMAP_EFR2); + timeout_h = serial_in(up, UART_OMAP_TO_H); + timeout_l = serial_in(up, UART_OMAP_TO_L); + serial_out(up, UART_OMAP_TO_H, 0xFF); + serial_out(up, UART_OMAP_TO_L, 0xFF); + serial_out(up, UART_OMAP_EFR2, 0x1); + serial_in(up, UART_IIR); + serial_out(up, UART_OMAP_EFR2, efr2); + serial_out(up, UART_OMAP_TO_H, timeout_h); + serial_out(up, UART_OMAP_TO_L, timeout_l); } /* Stop processing interrupts on input overrun */ -- 2.34.1