From mboxrd@z Thu Jan 1 00:00:00 1970 From: Douglas Anderson Subject: [PATCH 1/4] spi: For controllers that need realtime always use the pump thread Date: Fri, 10 May 2019 15:34:34 -0700 Message-ID: <20190510223437.84368-2-dianders@chromium.org> References: <20190510223437.84368-1-dianders@chromium.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Cc: linux-rockchip@lists.infradead.org, drinkcat@chromium.org, Guenter Roeck , briannorris@chromium.org, mka@chromium.org, Douglas Anderson , linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org To: Mark Brown , Benson Leung , Enric Balletbo i Serra Return-path: In-Reply-To: <20190510223437.84368-1-dianders@chromium.org> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-spi.vger.kernel.org If a controller specifies that it needs high priority for sending messages we should always schedule our transfers on the thread. If we don't do this we'll do the transfer in the caller's context which might not be very high priority. Signed-off-by: Douglas Anderson --- drivers/spi/spi.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 8eb7460dd744..0597f7086de3 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -1230,8 +1230,11 @@ static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread) return; } - /* If another context is idling the device then defer */ - if (ctlr->idling) { + /* + * If another context is idling the device then defer. + * If we are high priority then the thread should do the transfer. + */ + if (ctlr->idling || (ctlr->rt && !in_kthread)) { kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages); spin_unlock_irqrestore(&ctlr->queue_lock, flags); return; -- 2.21.0.1020.gf2820cf01a-goog