Hi, Greg Samsung users have reported that this reversion is required. I can help to port it back to 3.17-stable. I'll send it later.
Best regards -Lv > From: [email protected] [mailto:[email protected]] > Sent: Monday, November 10, 2014 12:12 PM > > > The patch below does not apply to the 3.17-stable tree. > If someone wants it applied there, or to any other stable or longterm > tree, then please email the backport, including the original git commit > id to <[email protected]>. > > thanks, > > greg k-h > > ------------------ original commit in Linus's tree ------------------ > > From df9ff91801da603079018f21a9412385b62f0f8e Mon Sep 17 00:00:00 2001 > From: Lv Zheng <[email protected]> > Date: Wed, 29 Oct 2014 11:33:43 +0800 > Subject: [PATCH] Revert "ACPI / EC: Add support to disallow QR_EC to be issued > before completing previous QR_EC" > MIME-Version: 1.0 > Content-Type: text/plain; charset=UTF-8 > Content-Transfer-Encoding: 8bit > > It is reported that the following commit breaks Samsung hardware: > Commit: 558e4736f2e1b0e6323adf7a5e4df77ed6cfc1a4. > Subject: ACPI / EC: Add support to disallow QR_EC to be issued before > completing previous QR_EC > > Which means the Samsung behavior conflicts with the Acer behavior. > > 1. Samsung may behave like: > [ +event 1 ] SCI_EVT set > [ +event 2 ] SCI_EVT set > write QR_EC > read event > [ -event 1 ] SCI_EVT clear > Without the above commit, Samsung can work: > [ +event 1 ] SCI_EVT set > [ +event 2 ] SCI_EVT set > write QR_EC > CAN prepare next QR_EC as SCI_EVT=1 > read event > [ -event 1 ] SCI_EVT clear > write QR_EC > read event > [ -event 2 ] SCI_EVT clear > With the above commit, Samsung cannot work: > [ +event 1 ] SCI_EVT set > [ +event 2 ] SCI_EVT set > write QR_EC > read event > [ -event 1 ] SCI_EVT clear > CANNOT prepare next QR_EC as SCI_EVT=0 > 2. Acer may behave like: > [ +event 1 ] SCI_EVT set > [ +event 2 ] > write QR_EC > read event > [ -event 1 ] SCI_EVT clear > [ +event 2 ] SCI_EVT set > Without the above commit, Acer cannot work when there is only 1 event: > [ +event 1 ] SCI_EVT set > write QR_EC > can prepared next QR_EC as SCI_EVT=1 > read event > [ -event 1 ] SCI_EVT clear > CANNOT write QR_EC as SCI_EVT=0 > With the above commit, Acer can work: > [ +event 1 ] SCI_EVT set > [ +event 2 ] > write QR_EC > read event > [ -event 1 ] SCI_EVT set > can prepare next QR_EC because SCI_EVT=0 > CAN write QR_EC as SCI_EVT=1 > > Since Acer can also work with only the following commit applied: > Commit: 3afcf2ece453e1a8c2c6de19cdf06da3772a1b08 > Subject: ACPI / EC: Add support to disallow QR_EC to be issued when > SCI_EVT isn't set > commit 558e4736f2e1b0e6323adf7a5e4df77ed6cfc1a4 can be reverted. > > Fixes: 558e4736f2e1 (ACPI / EC: Add support to disallow QR_EC to be issued > ...) > Link: https://bugzilla.kernel.org/show_bug.cgi?id=44161 > Reported-and-tested-by: Ortwin Glück <[email protected]> > Signed-off-by: Lv Zheng <[email protected]> > Cc: 3.17+ <[email protected]> # 3.17+ > Signed-off-by: Rafael J. Wysocki <[email protected]> > > diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c > index 3d304ff7f095..31b699f2d088 100644 > --- a/drivers/acpi/ec.c > +++ b/drivers/acpi/ec.c > @@ -334,13 +334,13 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec > *ec, > pr_debug("***** Command(%s) started *****\n", > acpi_ec_cmd_string(t->command)); > start_transaction(ec); > - spin_unlock_irqrestore(&ec->lock, tmp); > - ret = ec_poll(ec); > - spin_lock_irqsave(&ec->lock, tmp); > if (ec->curr->command == ACPI_EC_COMMAND_QUERY) { > clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags); > pr_debug("***** Event stopped *****\n"); > } > + spin_unlock_irqrestore(&ec->lock, tmp); > + ret = ec_poll(ec); > + spin_lock_irqsave(&ec->lock, tmp); > pr_debug("***** Command(%s) stopped *****\n", > acpi_ec_cmd_string(t->command)); > ec->curr = NULL;
