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 4E12315218A; Tue, 2 Jul 2024 17:24:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719941058; cv=none; b=Gh/YZrNY4r7xDB6l9dza+y3W7bpAY0BvyQZhRx+4gk0pQNh8+dXskNipK3WNI1/VcZ6fyNMrxOGhAq5lmszsVNIuixVxaoEYoujLKU0DQMVrYmxJb7B52bL6PN2KGmLm99w3Irpc9y0PMDWan3fFC1qCqOStTdYXHBrfdctBmXs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719941058; c=relaxed/simple; bh=tBDlXoEI8Yx1Y7gI8pAupH1O9nN3v7Ev15AJLofoLGc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Sm9Om7GoT6icWwmQAGxOjwHjxxv7H+Wm6xH/TgkQX8XneX+QEkFFnzCkt3T6O/qbS8dyWybt6uVx2u543DMKWB+oou79+E5vI8jrxIqsA1vKSoS1KJCQXR2hMs1m+mA/BBpmvqKZx+dpOEE+5O/uDg3U8iWE9O2r9dR5UgYfFu4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=tunPFUOP; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="tunPFUOP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id ADF2CC116B1; Tue, 2 Jul 2024 17:24:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1719941058; bh=tBDlXoEI8Yx1Y7gI8pAupH1O9nN3v7Ev15AJLofoLGc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tunPFUOPSy3SMLV1VY2pj7sD/vtsid/oYZrcQ9IWzxVo0OH+vGYJ/aDAJavEqjcsC T1kTqtqXhwzrykZ+X2EUi9ZqecjZQttrxU872av1JkecWIMLNlNCazGFVEqsmgL6uW +p8wFEAEMXoQHWgxYio4m/jB8f0HGBg0uAgvSAu4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Udit Kumar Subject: [PATCH 6.6 116/163] serial: 8250_omap: Implementation of Errata i2310 Date: Tue, 2 Jul 2024 19:03:50 +0200 Message-ID: <20240702170237.446836585@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240702170233.048122282@linuxfoundation.org> References: <20240702170233.048122282@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: Udit Kumar commit 9d141c1e615795eeb93cd35501ad144ee997a826 upstream. As per Errata i2310[0], Erroneous timeout can be triggered, if this Erroneous interrupt is not cleared then it may leads to storm of interrupts, therefore apply Errata i2310 solution. [0] https://www.ti.com/lit/pdf/sprz536 page 23 Fixes: b67e830d38fa ("serial: 8250: 8250_omap: Fix possible interrupt storm on K3 SoCs") Cc: stable@vger.kernel.org Signed-off-by: Udit Kumar Link: https://lore.kernel.org/r/20240619105903.165434-1-u-kumar1@ti.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_omap.c | 25 ++++++++++++++++++++----- 1 file changed, 20 insertions(+), 5 deletions(-) --- a/drivers/tty/serial/8250/8250_omap.c +++ b/drivers/tty/serial/8250/8250_omap.c @@ -165,6 +165,10 @@ static u32 uart_read(struct omap8250_pri return readl(priv->membase + (reg << OMAP_UART_REGSHIFT)); } +/* Timeout low and High */ +#define UART_OMAP_TO_L 0x26 +#define UART_OMAP_TO_H 0x27 + /* * Called on runtime PM resume path from omap8250_restore_regs(), and * omap8250_set_mctrl(). @@ -646,13 +650,24 @@ static irqreturn_t omap8250_irq(int irq, /* * 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, UART_OMAP_EFR2_TIMEOUT_BEHAVE); + 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 */