From patchwork Mon Jun 24 16:56:56 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kumar, Udit" X-Patchwork-Id: 807199 Received: from lelv0142.ext.ti.com (lelv0142.ext.ti.com [198.47.23.249]) (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 A85AF2F24; Mon, 24 Jun 2024 16:57:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.47.23.249 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719248257; cv=none; b=dPl0lh7MNpRdUlqKCa15WQWmBzcaZ2vOgY69KvSjT+u0uCCRO3Qk0SRR7YIiDpamvbbIN+MOe55MAQFDfzcq/iIArtvw5RQOdSV4SrliWuTvITTkquEjXmPLHDc4avYI0Mstjmxbk0ayMLl4cIc/R0y8iUaX84kESG814qFmoPU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719248257; c=relaxed/simple; bh=i7FvkIi7YpEMb5yfJJghsk01zW9gXtkJZ52MSXXo7I4=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=ElNiD9F7p19KTLN7dYesP6mWs6XSZ2bGIORz5V8aFu5oL2WLOLgsYT9OCsmhMeDs3ThfoIR0UyZf3sHNrCSkeTjrU06QN5t8IXJgyku5NbeRz285lwZibps4viecXrHQYYXvaZ01YBiOR8iPkHGeQlyUPiPkczwmTBEBm3xMouA= 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=RQCIfJbj; arc=none smtp.client-ip=198.47.23.249 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="RQCIfJbj" Received: from fllv0035.itg.ti.com ([10.64.41.0]) by lelv0142.ext.ti.com (8.15.2/8.15.2) with ESMTP id 45OGv8SV119219; Mon, 24 Jun 2024 11:57:08 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1719248228; bh=twcPzD28GFzdRCNUIgA67wCdCEnWmVKCRedJShWMmmU=; h=From:To:CC:Subject:Date; b=RQCIfJbjtgVNpNomStUW061F58GXL4gs4mY+Yf7ftQSRyNDJrNWKPZMuB3ukCxJQg TrDHbI9+OawMsfOQbxLd5433BF6Qh8gj+FEw+mFfmdO9CMo6n7rI2Ksy5pYfyCpRcM LKOsHaPE+yoiamJ2GUtOERstKNhi7i4UHXR5bUEE= Received: from DFLE109.ent.ti.com (dfle109.ent.ti.com [10.64.6.30]) by fllv0035.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 45OGv8FG063614 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 24 Jun 2024 11:57:08 -0500 Received: from DFLE109.ent.ti.com (10.64.6.30) by DFLE109.ent.ti.com (10.64.6.30) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23; Mon, 24 Jun 2024 11:57:08 -0500 Received: from lelvsmtp5.itg.ti.com (10.180.75.250) by DFLE109.ent.ti.com (10.64.6.30) 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; Mon, 24 Jun 2024 11:57:08 -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 45OGv4Jc032912; Mon, 24 Jun 2024 11:57:05 -0500 From: Udit Kumar To: , , CC: , , , , , , , , Udit Kumar , Subject: [PATCH v4] serial: 8250_omap: Implementation of Errata i2310 Date: Mon, 24 Jun 2024 22:26:56 +0530 Message-ID: <20240624165656.2634658-1-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 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 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 Reviewed-by: Vignesh Raghavendra --- Test logs: https://gist.github.com/uditkumarti/48e239540db4e761861fbd1d7d31cfed Change logs Changes in v4: - Reverted fifo empty check before applying errata Link to v3: https://lore.kernel.org/all/20240619105903.165434-1-u-kumar1@ti.com/ Changes in v3: - CC stable in commit message Link to v2: https://lore.kernel.org/all/20240617052253.2188140-1-u-kumar1@ti.com/ Changes in v2: - Added Fixes Tag and typo correction in commit message - Corrected bit position to UART_OMAP_EFR2_TIMEOUT_BEHAVE Link to v1 https://lore.kernel.org/all/20240614061314.290840-1-u-kumar1@ti.com/ drivers/tty/serial/8250/8250_omap.c | 22 +++++++++++++++++++--- 1 file changed, 19 insertions(+), 3 deletions(-) diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c index 170639d12b2a..1af9aed99c65 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 +667,25 @@ 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); + 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 */