From patchwork Mon Jun 24 13:31:32 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johan Hovold X-Patchwork-Id: 13709508 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 78C31143743; Mon, 24 Jun 2024 13:31:41 +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=1719235901; cv=none; b=KyUQwtm67euxEs/jEzXYZ3sdGK2BZnySRTTrLX1TIdRynYdFteRybWkJRwsugPkg9dGL0JjGMhE9Aq0SXtM8WBR856/vJ+Xbzi2wuOjag5yXBmdRzzYG+sMOoPzXePVGDFHfQ24j1oMkNH1OcLRGsM8gPMwNGZg4gBUoV0mU2ZA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719235901; c=relaxed/simple; bh=vL7M6HIfjIdiY9ehdOVpJ0ONlHrr4nW+odyhP3l9jXE=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=mZTVhY7CdD9ppKcDIYwh2NQ0QxDgl+lTUz8mHRSekglAqzV2CCTE9ZDG2+gLMpu6ijK5hBYW+dgwxnPGb3QTh4YeBh3u4ZUVVdYfFAiNYA/DTQu0Ki6X3UQqSVjqLk0ukwCQb0GQVJh/IxoCiuZoRNq0QEPkzZc87QdCLBuK+gs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=qNjCBPS0; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="qNjCBPS0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 17136C2BBFC; Mon, 24 Jun 2024 13:31:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1719235901; bh=vL7M6HIfjIdiY9ehdOVpJ0ONlHrr4nW+odyhP3l9jXE=; h=From:To:Cc:Subject:Date:From; b=qNjCBPS0HAv5PDH1zqwns6xxdIdHEnYpu5G8mIHJQdiO5lLwTehGX/pyaDIZ7sGa6 Xv/grLpqvWyzAundeCK8IzaBd0gfEMG6CgLF0jQF7JYqnC3JsolpBkDmuzNp0QdI7s ewyG3eDO1+0LqK7STelr4guiz2pHtS4JfcHnScwGIro6TttlfCo4a8CdeC4tZhAB9k 1M6ViqOWUQntlhF8jl4kA63WRmtW1rbVMTdIg5U5ull6/ZKbEu7H7JLgMrI38KrYWq RhMS2iEZiApT7U888frsBNg0cYdXq4sn3KhQHzD4YQYFQBJ8n//Rxs5PNciIlxWwJ1 UZnpXPFtfZiAQ== Received: from johan by xi.lan with local (Exim 4.97.1) (envelope-from ) id 1sLjnO-000000001wS-0bQn; Mon, 24 Jun 2024 15:31:46 +0200 From: Johan Hovold To: Greg Kroah-Hartman , Jiri Slaby Cc: Konrad Dybcio , Douglas Anderson , Bjorn Andersson , linux-arm-msm@vger.kernel.org, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, Johan Hovold Subject: [PATCH 0/3] serial: qcom-geni: fix lockups Date: Mon, 24 Jun 2024 15:31:32 +0200 Message-ID: <20240624133135.7445-1-johan+linaro@kernel.org> X-Mailer: git-send-email 2.44.1 Precedence: bulk X-Mailing-List: linux-arm-msm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Since 6.10-rc1, Qualcomm machines with a serial port can easily lock up hard, for example, when stopping a getty on reboot. The first patch in this series fixes this severe regression by restoring the pre-6.10-rc1 behaviour of printing additional characters when flushing the tx buffer. The second patch fixes a long-standing issue in the GENI driver which can lead to a soft lock up when using software flow control and on suspend. The third patch, addresses the old issue with additional characters being printing when flushing the buffer. Note that timeouts used when clearing the tx fifo are a bit excessive since I'm reusing the current qcom_geni_serial_poll_bit() helper for now. I think at least the first patch should be merged for rc6 while we consider the best way forward to address the remaining issues. Doug has posted an alternative series of fixes here that depends on reworking the driver a fair bit here: https://lore.kernel.org/lkml/20240610222515.3023730-1-dianders@chromium.org/ Johan Johan Hovold (3): serial: qcom-geni: fix hard lockup on buffer flush serial: qcom-geni: fix soft lockup on sw flow control and suspend serial: qcom-geni: fix garbage output after buffer flush drivers/tty/serial/qcom_geni_serial.c | 36 +++++++++++++++++++-------- 1 file changed, 25 insertions(+), 11 deletions(-)