Messages in this thread Patch in this message | | | From | Tomas Winkler <> | Subject | [char-misc-next 2/4] mei: pxp: recover from recv fail under memory pressure | Date | Wed, 11 Oct 2023 14:01:55 +0300 |
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From: Alexander Usyskin <alexander.usyskin@intel.com>
Under memory pressure recv fails due to kmalloc failure, and if drivers(pxp) retry send/receive, send blocks indefinitely. Send without recv leaves the channel in a bad state.
Retry send attempt after small timeout and reset the channel if the retry failed on kmalloc failure too.
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com> Signed-off-by: Alan Previn <alan.previn.teres.alexis@intel.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> --- drivers/misc/mei/pxp/mei_pxp.c | 25 ++++++++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-)
diff --git a/drivers/misc/mei/pxp/mei_pxp.c b/drivers/misc/mei/pxp/mei_pxp.c index 2dcb9169e404c3bcbbccc7b4..c6cdd6a47308ebcc72f34c38 100644 --- a/drivers/misc/mei/pxp/mei_pxp.c +++ b/drivers/misc/mei/pxp/mei_pxp.c @@ -11,6 +11,7 @@ * negotiation messages to ME FW command payloads and vice versa. */ +#include <linux/delay.h> #include <linux/module.h> #include <linux/slab.h> #include <linux/mei.h> @@ -61,16 +62,38 @@ mei_pxp_receive_message(struct device *dev, void *buffer, size_t size) { struct mei_cl_device *cldev; ssize_t byte; + bool retry = false; if (!dev || !buffer) return -EINVAL; cldev = to_mei_cl_device(dev); +retry: byte = mei_cldev_recv(cldev, buffer, size); if (byte < 0) { dev_dbg(dev, "mei_cldev_recv failed. %zd\n", byte); - return byte; + if (byte != -ENOMEM) + return byte; + + /* Retry the read when pages are reclaimed */ + msleep(20); + if (!retry) { + retry = true; + goto retry; + } else { + dev_warn(dev, "No memory on data receive after retry, trying to reset the channel...\n"); + byte = mei_cldev_disable(cldev); + if (byte < 0) + dev_warn(dev, "mei_cldev_disable failed. %zd\n", byte); + /* + * Explicitly ignoring disable failure, + * enable may fix the states and succeed + */ + byte = mei_cldev_enable(cldev); + if (byte < 0) + dev_err(dev, "mei_cldev_enable failed. %zd\n", byte); + } } return byte; -- 2.41.0
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