Prashanth Prakash wrote:
+static int check_pcc_chan(void)
+{
+ int ret = -EIO;
+ struct acpi_pcct_shared_memory __iomem *generic_comm_base = pcc_comm_addr;
+ ktime_t next_deadline = ktime_add(ktime_get(), deadline);
+
+ /* Retry in case the remote processor was too slow to catch up. */
+ while (!ktime_after(ktime_get(), next_deadline)) {
+ if (readw_relaxed(&generic_comm_base->status) & PCC_CMD_COMPLETE) {
+ ret = 0;
+ break;
+ }
+ /*
+ * Reducing the bus traffic in case this loop takes longer than
+ * a few retries.
+ */
+ udelay(3);
+ }
Like I said last time, you really should use
readq_relaxed_poll_timeout(), which does exactly the same thing as this
loop, but more elegantly. I think this will work:
u32 status;
ret = readq_relaxed_poll_timeout(&generic_comm_base->status, status,
status & PCC_CMD_COMPLETE, 3, deadline);
return ret ? -EIO : 0;
...
deadline = NUM_RETRIES * cppc_ss->latency;
This lets you completely eliminate all usage of ktime. You can
eliminate the global variable 'deadline' also, if you can figure out how
to pass the cppc_ss object to check_pcc_chan().
- /* Wait for a nominal time to let platform process command. */
- udelay(cmd_latency);
-
- /* Retry in case the remote processor was too slow to catch up. */
- for (retries = NUM_RETRIES; retries > 0; retries--) {
- if (readw_relaxed(&generic_comm_base->status) & PCC_CMD_COMPLETE) {
- result = 0;
- break;
- }
- }
+ /*
+ * For READs we need to ensure the cmd completed to ensure
+ * the ensuing read()s can proceed. For WRITEs we dont care
"don't"
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