On Thu, 01 Nov 2018 13:38:49 +0100, Rohit kumar wrote: > > Remove no_pcm check to invoke pcm_new() for backend dai-links > too. This fixes crash in hdmi codec driver during hdmi_codec_startup() > while accessing chmap_info struct. chmap_info struct memory is > allocated in pcm_new() of hdmi codec driver which is not invoked > in case of DPCM when hdmi codec driver is part of backend dai-link. > > Below is the crash stack: > > [ 61.635493] Unable to handle kernel NULL pointer dereference at virtual > address 00000018 > .. > [ 61.666696] CM = 0, WnR = 1 > [ 61.669778] user pgtable: 4k pages, 39-bit VAs, pgd = ffffffc0d6633000 > [ 61.676526] [0000000000000018] *pgd=0000000153fc8003, > *pud=0000000153fc8003, *pmd=0000000000000000 > [ 61.685793] Internal error: Oops: 96000046 [#1] PREEMPT SMP > [ 61.722955] CPU: 7 PID: 2238 Comm: aplay Not tainted 4.14.72 #21 > .. > [ 61.740269] PC is at hdmi_codec_startup+0x124/0x164 > [ 61.745308] LR is at hdmi_codec_startup+0xe4/0x164 > > Signed-off-by: Rohit kumar <rohi...@codeaurora.org>
Did you check whether all drivers have no side-effect by this change? The hdmi-codec isn't the only driver that has pcm_new ops, so we have to make sure that such a fundamental change wouldn't bring any regressions. thanks, Takashi
