ACPI / EC: Remove duplicated ec_wait_ibf0() waiter (9b80f0f7) · Commits · 戴 / test

After we've added the first command byte write into advance_transaction(), the IBF=0 waiter is duplicated with the command completion waiter implemented in the ec_poll() because: If IBF=1 blocked the first command byte write invoked in the task context ec_poll(), it would be kicked off upon IBF=0 interrupt or timed out and retried again in the task context. Remove this seperate and duplicate IBF=0 waiter. By doing so we can reduce the overall number of times to access the EC_SC(R) status register. Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891 Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931 Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911 Reported-and-tested-by:

Gareth Williams <gareth@garethwilliams.me.uk> Reported-and-tested-by:

Hans de Goede <jwrdegoede@fedoraproject.org> Reported-by:

Barton Xu <tank.xuhan@gmail.com> Tested-by:

Steffen Weber <steffen.weber@gmail.com> Tested-by:

Arthur Chen <axchen@nvidia.com> Signed-off-by:

Lv Zheng <lv.zheng@intel.com> Cc: All applicable <stable@vger.kernel.org> Signed-off-by:

Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/ec.c

+1 −26

Original line number	Diff line number	Diff line
		@@ -281,23 +281,6 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
		return ret;
		}

		static int ec_check_ibf0(struct acpi_ec *ec)
		{
		u8 status = acpi_ec_read_status(ec);
		return (status & ACPI_EC_FLAG_IBF) == 0;
		}

		static int ec_wait_ibf0(struct acpi_ec *ec)
		{
		unsigned long delay = jiffies + msecs_to_jiffies(ec_delay);
		/* interrupt wait manually if GPE mode is not active */
		while (time_before(jiffies, delay))
		if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
		msecs_to_jiffies(1)))
		return 0;
		return -ETIME;
		}

		static int acpi_ec_transaction(struct acpi_ec ec, struct transaction t)
		{
		int status;
		@@ -318,12 +301,6 @@ static int acpi_ec_transaction(struct acpi_ec ec, struct transaction t)
		goto unlock;
		}
		}
		if (ec_wait_ibf0(ec)) {
		pr_err("input buffer is not empty, "
		"aborting transaction\n");
		status = -ETIME;
		goto end;
		}
		pr_debug("transaction start (cmd=0x%02x, addr=0x%02x)\n",
		t->command, t->wdata ? t->wdata[0] : 0);
		/* disable GPE during transaction if storm is detected */
		@@ -347,7 +324,6 @@ static int acpi_ec_transaction(struct acpi_ec ec, struct transaction t)
		set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
		}
		pr_debug("transaction end\n");
		end:
		if (ec->global_lock)
		acpi_release_global_lock(glk);
		unlock:
		@@ -653,8 +629,7 @@ static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
		spin_lock_irqsave(&ec->lock, flags);
		advance_transaction(ec);
		spin_unlock_irqrestore(&ec->lock, flags);
		if (ec_transaction_completed(ec) &&
		(acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
		if (ec_transaction_completed(ec)) {
		wake_up(&ec->wait);
		ec_check_sci(ec, acpi_ec_read_status(ec));
		}

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