drm/amd/display: use proper context for logging
authorJiri Slaby (SUSE) <jirislaby@kernel.org>
Thu, 23 Jul 2026 04:25:48 +0000 (06:25 +0200)
committerAlex Deucher <alexander.deucher@amd.com>
Wed, 29 Jul 2026 00:01:24 +0000 (20:01 -0400)
commit114b42507b6a23d9d24e24e4ef165233332c64d4
treeeefbaf37f208f82b338e4ba15f4e07443ca65416
parent5e70f6804b4d6256058c360b10e044ee04ea4a4e
drm/amd/display: use proper context for logging

The same as the rest of the code, get_ss_info_from_atombios() uses
calc_pll_cs->ctx->logger for logging. But calc_pll_cs->ctx is
initialized only later in calc_pll_max_vco_construct(). Therefore, any
output using DC_LOG_SYNC() leads to a NULL pointer deference in
get_ss_info_from_atombios().

According to Sashiko, the very same problem exists in
dce112_get_pix_clk_dividers() and dcn3_get_pix_clk_dividers() too.

To avoid accessing the NULL context, use clk_src->base.ctx->logger
everywhere. That context in base is initialized earlier in
dce110_clk_src_construct() and dce112_clk_src_construct(). Before
get_ss_info_from_atombios() or Sashiko's get_pix_clk_dividers functions
above are actually called. This is done by redefining DC_LOGGER to
CTX->logger.

Before:
dce110_clk_src_construct() did:
 -> sets clk_src->base.ctx = ctx;
 -> ss_info_from_atombios_create()
   -> get_ss_info_from_atombios()   <- uses calc_pll_cs->ctx  # BOOM
 -> calc_pll_max_vco_construct()    <- sets calc_pll_cs->ctx

After:
dce110_clk_src_construct() does:
 -> sets clk_src->base.ctx = ctx;
 -> ss_info_from_atombios_create()
   -> get_ss_info_from_atombios()   <- uses clk_src->base.ctx

Closes: https://bugzilla.suse.com/show_bug.cgi?id=1271175
Closes: https://lore.kernel.org/all/a9ee54e6-2413-4156-9bde-d528ae3c63a3@kernel.org/
Fixes: 1296423bf23c ("drm/amd/display: define DC_LOGGER for logger")
Reviewed-by: Bhawanpreet Lakha <bhawanpreet.lakha@amd.com>
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Lakha, Bhawanpreet <Bhawanpreet.Lakha@amd.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Leo Li <sunpeng.li@amd.com>
Cc: Rodrigo Siqueira <siqueira@igalia.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: David Airlie <airlied@gmail.com>
Cc: Simona Vetter <simona@ffwll.ch>
Cc: amd-gfx@lists.freedesktop.org
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 6f16fcbb0c46a87e3d9685407e906573d60104b0)
Cc: stable@vger.kernel.org
drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c