redonkable/alistair23-linux
redonkable/alistair23-linux
1
0
Fork 0
Code Releases Activity

drm/ast: Don't assume DVO enabled means SIL164 on uninitialized chips

Browse source 
It looks like the AST2400 comes up with the DVO enable bit set,
which causes us to incorrectly assume we have a SIL164 regardless
of the value of the scratch registers setup by the BMC firmware.

So let's limit that test to the case where the chip has already
been setup by a BIOS.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This commit is contained in:
Benjamin Herrenschmidt 2014-09-04 17:50:21 +10:00 committed by Dave Airlie
parent 261a3ad426
commit 42fb142744
1 changed files with 10 additions and 4 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

14
drivers/gpu/drm/ast/ast_main.c
View file

@ -158,16 +158,22 @@ static int ast_detect_chip(struct drm_device *dev, bool *need_post)
/*
* VGACRA3 Enhanced Color Mode Register, check if DVO is already
* enabled, in that case, assume we have a SIL164 TMDS transmitter
*
* Don't make that assumption if we the chip wasn't enabled and
* is at power-on reset, otherwise we'll incorrectly "detect" a
* SIL164 when there is none.
*/
jreg = ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xa3, 0xff);
if (jreg & 0x80)
ast->tx_chip_type = AST_TX_SIL164;
if (!*need_post) {
jreg = ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xa3, 0xff);
if (jreg & 0x80)
ast->tx_chip_type = AST_TX_SIL164;
}
if ((ast->chip == AST2300) || (ast->chip == AST2400)) {
/*
* On AST2300 and 2400, look the configuration set by the SoC in
* the SOC scratch register #1 bits 11:8 (interestingly marked
* as "reserved" in the spec
* as "reserved" in the spec)
*/
jreg = ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xd1, 0xff);
switch (jreg) {