On Fri, Nov 21, 2014 at 02:33:30PM +0800, Lv Zheng wrote: > commit 558e4736f2e1b0e6323adf7a5e4df77ed6cfc1a4 upstream. > > 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. You changed the text here from the original, which isn't ok. I used the original text instead. greg k-h -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html