From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.andi.de1.cc (mail.andi.de1.cc [178.238.236.174]) (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 6C8341AE01F; Mon, 14 Oct 2024 15:22:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=178.238.236.174 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728919365; cv=none; b=MjwUeAsVZbtvmk5ojjtb2N97ksn1eVRe2SZ5dZx9/oO/rxsL7J25FDPTW/LXJ0+YkmMZKJ/G/XjIdqy1ypX4uJk18+pelkBuDzFlt13kb4DkNkwSQRe7CK7OQM7JIqFBd2lmOX2sgpj5sgofmfr6g7FMu7nzh3WgsijV9xLOeRM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728919365; c=relaxed/simple; bh=riXFOTomC+rJMGpA1bmlrqeX3Yd+ngcuOvBAzntGC3Y=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=KUETXbv+L6/Aagd1h2138a4JFeELk13+Yyr7Jer07lpbkydqppPlj1t9gqwV7hsZb3jzNgVcD2y3oF+s+e1Ftf1jXzPC39mo5i3/6qba2kq8pgsD/6luKtOhxi9OmG2pfCmyUXG+blCrYwhgTpEAdlJ17RjB5p0K3tRGjsGEBq8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=kemnade.info; spf=pass smtp.mailfrom=kemnade.info; dkim=pass (2048-bit key) header.d=kemnade.info header.i=@kemnade.info header.b=HzQokqH2; arc=none smtp.client-ip=178.238.236.174 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=kemnade.info Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kemnade.info Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kemnade.info header.i=@kemnade.info header.b="HzQokqH2" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=kemnade.info; s=20220719; h=References:In-Reply-To:Cc:From:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID; bh=riXFOTomC+rJMGpA1bmlrqeX3Yd+ngcuOvBAzntGC3Y=; b=HzQokqH2HhbTAwK0NvS/BSx/lN S+gpVOrdx1XnxxgppSHuLlOyRzSg1/TAGLw+Hv7IYnoXWkgYcFj0htDoLTAghLwy9vx9s6ivPlNdg rtqVtcqPsSA2ttFf4Vt4NvE6drpug/dFXTTLFSBohy2wQ9bs6KSgnSw72/GHlDlHoS7/5w7pIAPm0 qr4+KoYm2HsCSW/G0x1sn0fWpQBivOAcu961c1vgDhtNjLvVKTK96mLsLDgf31WtECME0qE0wNlga srHIudAXzkLkyWd8RP2Tbq5pDyFbP4wTsBDEosrzXuRZPgiiCIZ8BcM+Rs+um/q9P0beHkTSIOqWM onwvGadQ==; Date: Mon, 14 Oct 2024 17:22:37 +0200 From: Andreas Kemnade To: Bin Liu Cc: Judith Mendez , Santosh Shilimkar , Kevin Hilman , Linus Walleij , Bartosz Golaszewski , linux-omap@vger.kernel.org, linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, Bin Liu , linux-serial@vger.kernel.org Subject: Re: [PATCH RESEND 2/2] serial: 8250: omap: Move pm_runtime_get_sync Message-ID: <20241014172237.63e9625f@akair> In-Reply-To: <4297747A-8AB9-4E50-93FF-723672B6471C@gmail.com> References: <20241012142705.45948f7d@akair> <4297747A-8AB9-4E50-93FF-723672B6471C@gmail.com> X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-omap@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Am Sun, 13 Oct 2024 21:52:05 -0500 schrieb Bin Liu : > Hi, >=20 > Somehow this email wasn=E2=80=99t cc=E2=80=99d to my company email account > b-liu@ti.com, so I am replying from my personal email which > subscribed to the mailing list, and sorry if the formatting is wrong > since I am writing this response on my phone.=C2=A0 >=20 > On Oct 12, 2024, at 7:27=E2=80=AFAM, Andreas Kemnade > wrote: > >=20 > > =EF=BB=BFAm Fri, 11 Oct 2024 12:33:56 -0500 > > schrieb Judith Mendez : > >=20 > > Currently in omap_8250_shutdown, the dma->rx_running > >> flag is set to zero in omap_8250_rx_dma_flush. Next > >> pm_runtime_get_sync is called, which is a runtime > >> resume call stack which can re-set the flag. When the > >> call omap_8250_shutdown returns, the flag is expected > >> to be UN-SET, but this is not the case. This is causing > >> issues the next time UART is re-opened and omap_8250_rx_dma > >> is called. Fix by moving pm_runtime_get_sync before the > >> omap_8250_rx_dma_flush. > >>=20 > >> Signed-off-by: Bin Liu > >> Signed-off-by: Judith Mendez > >>=20 > > Is this a theorectical problem or some real practical problem? > > So you are running a system with runtime pm enabled on serial > > console. > > How did you come across this issue? > > I could run the serial console/getty with runtime pm autosuspend > > enabled without issues all the years. > >=20 > Yes this is a real issue reported on AM335x. Please see the report > linked below. >=20 > PROCESSOR-SDK-AM335X: Possible bug in 8250_omap UART driver - > Processors forum - Processors - TI E2E support forums e2e.ti.com >=20 >=20 Thanks for information, so it looks like material for backporting. Maybe add the link in the description and add the cc stable and=20 add back the fixes tag. Regards, Andreas