On Mon, Apr 3, 2017 at 4:55 PM, Nicolin Chen <nicoleotsuka@xxxxxxxxx> wrote: > On Mon, Apr 03, 2017 at 04:31:59PM -0700, Caleb Crome wrote: > >> > What's your test case for the alignment? >> >> I'm not sure what you are asking. The test case I'm testing is: >> connect SSI to AUD4 on wandboard & physically connect TX -> RX. (as >> per https://github.com/ccrome/linux-caleb-dev/wiki), then use atest to >> verify bit-perfection of TX->RX transmission. > > So your test case involve both TX and RX. That's why this change > would impact it. My understanding is: because you can not enable > TX and RX in the same time from user space but only through two > separate back-to-back system calls. So when the 2nd system call > happens (RX for example), the RE bit, supposed to be enabled by > this 2nd system call, has already been set by the 1st TX system > call -- there's some random data in the RX FIFO already. > >> >> > - regmap_update_bits(regs, CCSR_SSI_SCR, vals->scr, vals->scr); >> >> > + regmap_update_bits(regs, CCSR_SSI_SCR, >> >> > + CCSR_SSI_SCR_SSIEN | CCSR_SSI_SCR_TE | CCSR_SSI_SCR_RE, >> >> > + CCSR_SSI_SCR_SSIEN | CCSR_SSI_SCR_TE | CCSR_SSI_SCR_RE); >> > >> > However, this patch seems to merely set the RE bit. It shouldn't >> > affect that test case since the SSIEN bit is still set prior to >> > the TE bit. >> >> Heh, well, this patch causes audio to be utterly broken on >> multi-channel audio :-/ > > If possible, could you try to confirm what's the diff between the > two SCR values of before-regmap and after-regmap in your case? With this patch (broken audio, includes tx and rx, so 2 updates. Running atest software) ------------------------ Apr 4 00:35:03 arm kernel: [ 33.678451] Before update: 0x00001098 Apr 4 00:35:03 arm kernel: [ 33.682339] After update: 0x0000109f Apr 4 00:35:04 arm kernel: [ 33.687196] Before update: 0x0000109f Apr 4 00:35:04 arm kernel: [ 33.690916] After update: 0x0000109f Before this patch (working audio, running atest software) ------------------------ Apr 4 00:38:24 arm kernel: [ 68.261765] Before update: 0x00001098 Apr 4 00:38:24 arm kernel: [ 68.265653] After update: 0x0000109d Apr 4 00:38:24 arm kernel: [ 68.270865] Before update: 0x0000109d Apr 4 00:38:24 arm kernel: [ 68.274560] After update: 0x0000109f Oh what a difference 1 bit makes! -Caleb _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
