Hi. Thanks for Debian. Really. Thanks a lot.
I am using Debian Stretch.
My computer is a Toshiba Satellite L755D-S5204, AMDA6 with an Ati-Raedon HD6520G. I use an additional display, a LG Flatron M2241A.
Since Stretch do not recommend to install the catalyst drivers directly downloaded from ATI (I only got a frozen system AND a no-graphics-only-text Debian Stretch . . . . I am using the AMD/ATI drivers from the non-free debian stretch respositories.
In an update fron the last week, something stopped working. Debian no longer recognize the model and the resolution of the external display in automatic.
The only resolutions recognized were the three traditional resolutions for VGA. The highest 1024x768.
I have searched in Google and read the manuals (cvt, xrand, xorg.conf, and others), I also searched for info in Xorg... And found a workaround with ""cvt"" and ""xrand --newmode"" / ""xrand --addmode"" / and ""xrand --output"", so I can manually get the correct display resolution back to work... although I must type those again each time I turn on the computer.
But, that was working automatically.