From ca460f86521ed515d17dd1314f7b95183866f681 Mon Sep 17 00:00:00 2001 From: David Henningsson Date: Fri, 28 Feb 2014 07:56:58 +0100 Subject: [PATCH] ALSA: hda - Fix CORB reset to follow specification According to the HDA spec, we must write 1 to bit 15 on a CORBRP reset, read back 1, then write 0, then read back 0. This must be done while the DMA is not running. We accidentaly ended up writing back the 0 by using a writel instead of a writew to CORBWP. This caused occasional controller failure on Bay Trail hardware. [replaced error messages with dev_err() by tiwai] Signed-off-by: David Henningsson Signed-off-by: Takashi Iwai --- sound/pci/hda/hda_intel.c | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-) diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index 6eb09418d08e..e8a9e87ac074 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -769,6 +769,8 @@ static int azx_alloc_cmd_io(struct azx *chip) static void azx_init_cmd_io(struct azx *chip) { + int timeout; + spin_lock_irq(&chip->reg_lock); /* CORB set up */ chip->corb.addr = chip->rb.addr; @@ -780,8 +782,28 @@ static void azx_init_cmd_io(struct azx *chip) azx_writeb(chip, CORBSIZE, 0x02); /* set the corb write pointer to 0 */ azx_writew(chip, CORBWP, 0); + /* reset the corb hw read pointer */ azx_writew(chip, CORBRP, ICH6_CORBRP_RST); + for (timeout = 1000; timeout > 0; timeout--) { + if ((azx_readw(chip, CORBRP) & ICH6_CORBRP_RST) == ICH6_CORBRP_RST) + break; + udelay(1); + } + if (timeout <= 0) + dev_err(chip->card->dev, "CORB reset timeout#1, CORBRP = %d\n", + azx_readw(chip, CORBRP)); + + azx_writew(chip, CORBRP, 0); + for (timeout = 1000; timeout > 0; timeout--) { + if (azx_readw(chip, CORBRP) == 0) + break; + udelay(1); + } + if (timeout <= 0) + dev_err(chip->card->dev, "CORB reset timeout#2, CORBRP = %d\n", + azx_readw(chip, CORBRP)); + /* enable corb dma */ azx_writeb(chip, CORBCTL, ICH6_CORBCTL_RUN); @@ -856,7 +878,7 @@ static int azx_corb_send_cmd(struct hda_bus *bus, u32 val) chip->rirb.cmds[addr]++; chip->corb.buf[wp] = cpu_to_le32(val); - azx_writel(chip, CORBWP, wp); + azx_writew(chip, CORBWP, wp); spin_unlock_irq(&chip->reg_lock); -- 2.11.0