From f5e6958919e0d70e3be8c30dfafae02ee16cfbf0 Mon Sep 17 00:00:00 2001 From: Francesco Dolcini Date: Tue, 28 Nov 2023 20:49:35 +0100 Subject: [PATCH] platform/surface: aggregator: fix recv_buf() return value MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit commit c8820c92caf0770bec976b01fa9e82bb993c5865 upstream. Serdev recv_buf() callback is supposed to return the amount of bytes consumed, therefore an int in between 0 and count. Do not return negative number in case of issue, when ssam_controller_receive_buf() returns ESHUTDOWN just returns 0, e.g. no bytes consumed, this keep the exact same behavior as it was before. This fixes a potential WARN in serdev-ttyport.c:ttyport_receive_buf(). Fixes: c167b9c7e3d6 ("platform/surface: Add Surface Aggregator subsystem") Cc: stable@vger.kernel.org Signed-off-by: Francesco Dolcini Reviewed-by: Maximilian Luz Link: https://lore.kernel.org/r/20231128194935.11350-1-francesco@dolcini.it Reviewed-by: Ilpo Järvinen Signed-off-by: Ilpo Järvinen Signed-off-by: Greg Kroah-Hartman --- drivers/platform/surface/aggregator/core.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/platform/surface/aggregator/core.c b/drivers/platform/surface/aggregator/core.c index 1a6373d..6152be3 100644 --- a/drivers/platform/surface/aggregator/core.c +++ b/drivers/platform/surface/aggregator/core.c @@ -231,9 +231,12 @@ static int ssam_receive_buf(struct serdev_device *dev, const unsigned char *buf, size_t n) { struct ssam_controller *ctrl; + int ret; ctrl = serdev_device_get_drvdata(dev); - return ssam_controller_receive_buf(ctrl, buf, n); + ret = ssam_controller_receive_buf(ctrl, buf, n); + + return ret < 0 ? 0 : ret; } static void ssam_write_wakeup(struct serdev_device *dev) -- 2.7.4