From 69f4eb9ff79556c1a3daf5af5573594c196f30cc Mon Sep 17 00:00:00 2001 From: Keith Busch Date: Wed, 6 Jun 2018 08:13:09 -0600 Subject: nvme-pci: make CMB SQ mod-param read-only A controller reset after a run time change of the CMB module parameter breaks the driver. An 'on -> off' will have the driver use NULL for the host memory queue, and 'off -> on' will use mismatched queue depth between the device and the host. We could fix both, but there isn't really a good reason to change this at run time anyway, compared to at module load time, so this patch makes parameter read-only after after modprobe. Signed-off-by: Keith Busch Reviewed-by: Sagi Grimberg Reviewed-by: Johannes Thumshirn Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- drivers/nvme/host/pci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/nvme') diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index d935aba0288f..cd7aec58a301 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -42,7 +42,7 @@ static int use_threaded_interrupts; module_param(use_threaded_interrupts, int, 0); static bool use_cmb_sqes = true; -module_param(use_cmb_sqes, bool, 0644); +module_param(use_cmb_sqes, bool, 0444); MODULE_PARM_DESC(use_cmb_sqes, "use controller's memory buffer for I/O SQes"); static unsigned int max_host_mem_size_mb = 128; -- cgit