platform: msm_shared: Wait until RPM has written the packet in SMEM
SMD driver uses a fixed delay before reading RPM response, but its
not gauranteed that RPM would respond in this fixed time. This leads
to race conditions where appsbl continues assuming RPM has updated
the response buffer. To fix this busy-wait until RPM has update the
data in SMEM. Also fix the updates to data read and state updated
flags. data_read should be set only for send buffer channel and
state_udpated should be set only when there is if_sigs change.
CRs-Fixed: 708794
Change-Id: I343f40bfee9e74a77bd79e455f900880d4c9b5e5
diff --git a/platform/msm_shared/smd.c b/platform/msm_shared/smd.c
index 6377e7e..dfb5b62 100644
--- a/platform/msm_shared/smd.c
+++ b/platform/msm_shared/smd.c
@@ -167,8 +167,20 @@
return -1;
}
- /* Clear the data_written flag */
- ch->port_info->ch1.data_written = 0;
+ /* Wait until the data updated in the smd buffer is equal to smd packet header*/
+ while ((ch->port_info->ch1.write_index - ch->port_info->ch1.read_index) < sizeof(smd_pkt_hdr))
+ {
+ /* Get the update info from memory */
+ arch_invalidate_cache_range((addr_t) ch->port_info, size);
+
+ if ((ch->port_info->ch1.read_index + sizeof(smd_pkt_hdr)) >= ch->fifo_size)
+ {
+ dprintf(CRITICAL, "At %d:%s:RX channel read index [%u] is greater than RX fifo size[%u]\n",
+ __LINE__,__func__, ch->port_info->ch1.read_index, ch->fifo_size);
+ return -1;
+ }
+ }
+
arch_invalidate_cache_range((addr_t)(ch->recv_buf + ch->port_info->ch1.read_index), sizeof(smd_hdr));
@@ -177,6 +189,21 @@
*len = smd_hdr.pkt_size;
+ /* Wait on the data being updated in SMEM before returing the response */
+ while ((ch->port_info->ch1.write_index - ch->port_info->ch1.read_index) < smd_hdr.pkt_size)
+ {
+ /* Get the update info from memory */
+ arch_invalidate_cache_range((addr_t) ch->port_info, size);
+
+ if ((ch->port_info->ch1.read_index + sizeof(smd_hdr) + smd_hdr.pkt_size) >= ch->fifo_size)
+ {
+ dprintf(CRITICAL, "At %d:%s:RX channel read index [%u] is greater than RX fifo size[%u]\n",
+ __LINE__,__func__, ch->port_info->ch1.read_index, ch->fifo_size);
+ return -1;
+ }
+ }
+
+ /* We are good to return the response now */
return (uint8_t*)(ch->recv_buf + ch->port_info->ch1.read_index + sizeof(smd_hdr));
}
@@ -184,10 +211,12 @@
{
ch->port_info->ch1.read_index += sizeof(smd_pkt_hdr) + len;
+ /* Clear the data_written flag */
+ ch->port_info->ch1.data_written = 0;
+
/* Set the data_read flag */
- ch->port_info->ch1.data_read = 1;
+ ch->port_info->ch0.data_read = 1;
ch->port_info->ch0.mask_recv_intr = 1;
- ch->port_info->ch0.state_updated = 1;
dsb();
@@ -244,7 +273,6 @@
ch->port_info->ch0.data_written = 1;
ch->port_info->ch0.mask_recv_intr = 0;
- ch->port_info->ch0.state_updated = 1;
dsb();