From c781e1d4f3e23d5fc138dad2fd98ca0e0dd9c592 Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Thu, 7 May 2020 14:14:03 -0500 Subject: [PATCH 1/2] net: ipa: set DMA length in gsi_trans_cmd_add() When a command gets added to a transaction for the AP->command channel we set the DMA address of its scatterlist entry, but not its DMA length. Fix this bug. Signed-off-by: Alex Elder Signed-off-by: David S. Miller --- drivers/net/ipa/gsi_trans.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/net/ipa/gsi_trans.c b/drivers/net/ipa/gsi_trans.c index 2fd21d75367d..bdbfeed359db 100644 --- a/drivers/net/ipa/gsi_trans.c +++ b/drivers/net/ipa/gsi_trans.c @@ -399,13 +399,14 @@ void gsi_trans_cmd_add(struct gsi_trans *trans, void *buf, u32 size, /* assert(which < trans->tre_count); */ /* Set the page information for the buffer. We also need to fill in - * the DMA address for the buffer (something dma_map_sg() normally - * does). + * the DMA address and length for the buffer (something dma_map_sg() + * normally does). */ sg = &trans->sgl[which]; sg_set_buf(sg, buf, size); sg_dma_address(sg) = addr; + sg_dma_len(sg) = sg->length; info = &trans->info[which]; info->opcode = opcode; From 2c4bb8093c3bfebc8113c683a5de83c64d43514c Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Thu, 7 May 2020 14:14:04 -0500 Subject: [PATCH 2/2] net: ipa: use tag process on modem crash One part of recovering from a modem crash is performing a "tag sequence" of several IPA immediate commands, to clear the hardware pipeline. The sequence ends with a data transfer request on the command endpoint (which is not otherwise done). Unfortunately, attempting to do the data transfer led to a hang, so that request plus two other commands were commented out. The previous commit fixes the bug that was causing that hang. And with that bug fixed we can properly issue the tag sequence when the modem crashes, to return the hardware to a known state. Signed-off-by: Alex Elder Signed-off-by: David S. Miller --- drivers/net/ipa/ipa_cmd.c | 14 +++----------- 1 file changed, 3 insertions(+), 11 deletions(-) diff --git a/drivers/net/ipa/ipa_cmd.c b/drivers/net/ipa/ipa_cmd.c index d226b858742d..cee417181f98 100644 --- a/drivers/net/ipa/ipa_cmd.c +++ b/drivers/net/ipa/ipa_cmd.c @@ -628,23 +628,15 @@ static void ipa_cmd_transfer_add(struct gsi_trans *trans, u16 size) void ipa_cmd_tag_process_add(struct gsi_trans *trans) { - ipa_cmd_register_write_add(trans, 0, 0, 0, true); -#if 1 - /* Reference these functions to avoid a compile error */ - (void)ipa_cmd_ip_packet_init_add; - (void)ipa_cmd_ip_tag_status_add; - (void) ipa_cmd_transfer_add; -#else struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi); - struct gsi_endpoint *endpoint; + struct ipa_endpoint *endpoint; endpoint = ipa->name_map[IPA_ENDPOINT_AP_LAN_RX]; + + ipa_cmd_register_write_add(trans, 0, 0, 0, true); ipa_cmd_ip_packet_init_add(trans, endpoint->endpoint_id); - ipa_cmd_ip_tag_status_add(trans, 0xcba987654321); - ipa_cmd_transfer_add(trans, 4); -#endif } /* Returns the number of commands required for the tag process */