[PATCH v2 6/6] ACPI / EC: Remove non-root-caused busy polling quirks.

[Lv Zheng]

We have fixed a lot of race issues in the EC driver recently.

The following commit introduces MSI udelay()/msleep() quirk to MSI laptops
to make EC firmware working for bug 12011 without root causing any EC
driver race issues:
  Commit: 5423a0cb3f74c16e90683f8ee1cec6c240a9556e
  Subject: ACPI: EC: Add delay for slow MSI controller
  Commit: 34ff4dbccccce54c83b1234d39b7ad9e548a75dd
  Subject: ACPI: EC: Separate delays for MSI hardware

The following commit extends ECDT validation quirk to MSI laptops to make
EC driver locating EC registers properly for bug 12461:
  Commit: a5032bfdd9c80e0231a6324661e123818eb46ecd
  Subject: ACPI: EC: Always parse EC device
This is a different quirk than the MSI udelay()/msleep() quirk. This patch
keeps validating ECDT for only "Micro-Star MS-171F" as reported.

The following commit extends MSI udelay()/msleep() quirk to Quanta laptops
to make EC firmware working for bug 20242, there is no requirement to
validate ECDT for Quanta laptops:
  Commit: 534bc4e3d27096e2f3fc00c14a20efd597837a4f Mon Sep 17 00:00:00 2001
  Subject: ACPI EC: enable MSI workaround for Quanta laptops

The following commit extends MSI udelay()/msleep() quirk to Clevo laptops
to make EC firmware working for bug 77431, there is no requirement to
validate ECDT for Clevo laptops:
  Commit: 777cb382958851c88763253fe00a26529be4c0e9
  Subject: ACPI / EC: Add msi quirk for Clevo W350etq

All udelay()/msleep() quirks for MSI/Quanta/Clevo seem to be the wrong
fixes generated without fixing the EC driver race issues.
And even if it is not wrong, the guarding can be covered by the following
commits in wait polling mode:
  Commit: 9e295ac14d6a59180beed0735e6a504c2ee87761
  Subject: ACPI / EC: Reduce ec_poll() by referencing the last register access timestamp.
  Commit: right before this commit
  Subject: ACPI / EC: Merge register access guarding logics.
The only case that is not covered is the inter-transaction guarding. And
there is no evidence that we need the inter-transaction guarding upon
reading the noted bug entries.

So it is time to remove the quirks and let the users to try again. If there
is a regression, the only thing we need to do is to restore the
inter-transaction guarding for the reported platforms.

Reference: https://bugzilla.kernel.org/show_bug.cgi?id=12011
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=12461
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=20242
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=77431
Signed-off-by: Lv Zheng <lv.zheng@xxxxxxxxx>
---
 drivers/acpi/ec.c |   35 +++--------------------------------
 1 file changed, 3 insertions(+), 32 deletions(-)

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 846e0617..149b5e7 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -1269,15 +1269,6 @@ static int ec_validate_ecdt(const struct dmi_system_id *id)
 	return 0;
 }
 
-/* EC firmware needs special polling mode, enable it */
-static int ec_use_busy_polling(const struct dmi_system_id *id)
-{
-	pr_debug("Detected the EC firmware requiring busy polling mode.\n");
-	ec_busy_polling = 1;
-	EC_FLAGS_VALIDATE_ECDT = 1;
-	return 0;
-}
-
 /*
  * Acer EC firmware refuses to respond QR_EC when SCI_EVT is not set, for
  * which case, we complete the QR_EC without issuing it to the firmware.
@@ -1320,29 +1311,9 @@ static struct dmi_system_id ec_dmi_table[] __initdata = {
 	DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
 	DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
 	{
-	ec_use_busy_polling, "MSI hardware", {
-	DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
-	{
-	ec_use_busy_polling, "MSI hardware", {
-	DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
-	{
-	ec_use_busy_polling, "MSI hardware", {
-	DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
-	{
-	ec_use_busy_polling, "MSI hardware", {
-	DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
-	{
-	ec_use_busy_polling, "Quanta hardware", {
-	DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
-	DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
-	{
-	ec_use_busy_polling, "Quanta hardware", {
-	DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
-	DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
-	{
-	ec_use_busy_polling, "Clevo W350etq", {
-	DMI_MATCH(DMI_SYS_VENDOR, "CLEVO CO."),
-	DMI_MATCH(DMI_PRODUCT_NAME, "W35_37ET"),}, NULL},
+	ec_validate_ecdt, "MSI MS-171F", {
+	DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
+	DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL},
 	{
 	ec_validate_ecdt, "ASUS hardware", {
 	DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
-- 
1.7.10

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