From bac3ef96b79ac7b7b44585f2c3a2adcd8732f7a2 Mon Sep 17 00:00:00 2001 From: Antonio Borneo Date: Sat, 14 Aug 2021 14:48:50 +0200 Subject: [PATCH] stlink: skip rw-misc commands with TCP server The main purpose of TCP server is to allow multiple clients to connect and share the same physical stlink. The commands RW MISC don't lock the communication between command and answer, thus cannot prevent another client to break this sequence. The commands are not supposed to be used in shared mode. Prevent the use of RW MISC commands on a (possibly) shared TCP backend. This degrades the overall performance, but the shared mode already adds its own overhead, so this is not really an issue. Change-Id: I713d912a269664859c8142932a9905d24b6d3caa Signed-off-by: Antonio Borneo Reviewed-on: https://review.openocd.org/c/openocd/+/6608 Tested-by: jenkins Reviewed-by: Tarek BOCHKATI --- src/jtag/drivers/stlink_usb.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/src/jtag/drivers/stlink_usb.c b/src/jtag/drivers/stlink_usb.c index 42b8cc2e8a..b51a0c2bac 100644 --- a/src/jtag/drivers/stlink_usb.c +++ b/src/jtag/drivers/stlink_usb.c @@ -4445,6 +4445,13 @@ static int stlink_usb_count_misc_rw_queue(void *handle, const struct dap_queue * if (!(h->version.flags & STLINK_F_HAS_RW_MISC)) return 0; + /* + * RW_MISC sequence doesn't lock the st-link, so are not safe in shared mode. + * Don't use it with TCP backend to prevent any issue in case of sharing. + * This further degrades the performance, on top of TCP server overhead. + */ + if (h->backend == &stlink_tcp_backend) + return 0; for (i = 0; i < len; i++) { if (q[i].cmd != CMD_MEM_AP_READ32 && q[i].cmd != CMD_MEM_AP_WRITE32) -- 2.30.2