[ALSA] sparc dbri: SMP fixes

The dbri driver hangs when used in kernel compiled with SMP
support due to inproper locking. The patch fixes it.

Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

1 files changed, 48 insertions, 17 deletions

diff --git a/sound/sparc/dbri.c b/sound/sparc/dbri.c
index 82d5e8072f2b..e4935fca12df 100644
--- a/sound/sparc/dbri.c
+++ b/sound/sparc/dbri.c
@@ -635,10 +635,16 @@ to send them to the DBRI.
 static void dbri_cmdwait(struct snd_dbri *dbri)
 {
         int maxloops = MAXLOOPS;
+        unsigned long flags;
 
         /* Delay if previous commands are still being processed */
-        while ((--maxloops) > 0 && (sbus_readl(dbri->regs + REG0) & D_P))
+        spin_lock_irqsave(&dbri->lock, flags);
+        while ((--maxloops) > 0 && (sbus_readl(dbri->regs + REG0) & D_P)) {
+                spin_unlock_irqrestore(&dbri->lock, flags);
                 msleep_interruptible(1);
+                spin_lock_irqsave(&dbri->lock, flags);
+        }
+        spin_unlock_irqrestore(&dbri->lock, flags);
 
         if (maxloops == 0) {
                 printk(KERN_ERR "DBRI: Chip never completed command buffer\n");
@@ -671,11 +677,12 @@ static s32 *dbri_cmdlock(struct snd_dbri * dbri, int len)
  * the last WAIT cmd and force DBRI to reread the cmd.
  * The JUMP cmd points to the new cmd string.
  * It also releases the cmdlock spinlock.
+ *
+ * Lock must not be held before calling this.
  */
 static void dbri_cmdsend(struct snd_dbri * dbri, s32 * cmd,int len)
 {
         s32 tmp, addr;
-        unsigned long flags;
         static int wait_id = 0;
 
         wait_id++;
@@ -706,12 +713,10 @@ static void dbri_cmdsend(struct snd_dbri * dbri, s32 * cmd,int len)
         }
 #endif
 
-        spin_lock_irqsave(&dbri->lock, flags);
         /* Reread the last command */
         tmp = sbus_readl(dbri->regs + REG0);
         tmp |= D_P;
         sbus_writel(tmp, dbri->regs + REG0);
-        spin_unlock_irqrestore(&dbri->lock, flags);
 
         dbri->cmdptr = cmd;
         spin_unlock(&dbri->cmdlock);
@@ -777,9 +782,9 @@ static void dbri_initialize(struct snd_dbri * dbri)
         dma_addr = dbri->dma_dvma + dbri_dma_off(cmd, 0);
         sbus_writel(dma_addr, dbri->regs + REG8);
         spin_unlock(&dbri->cmdlock);
-        dbri_cmdwait(dbri);
 
         spin_unlock_irqrestore(&dbri->lock, flags);
+        dbri_cmdwait(dbri);
 }
 
 /*
@@ -840,6 +845,9 @@ static void reset_pipe(struct snd_dbri * dbri, int pipe)
         dbri->pipes[pipe].first_desc = -1;
 }
 
+/*
+ * Lock must be held before calling this.
+ */
 static void setup_pipe(struct snd_dbri * dbri, int pipe, int sdp)
 {
         if (pipe < 0 || pipe > DBRI_MAX_PIPE) {
@@ -866,6 +874,9 @@ static void setup_pipe(struct snd_dbri * dbri, int pipe, int sdp)
         reset_pipe(dbri, pipe);
 }
 
+/*
+ * Lock must be held before calling this.
+ */
 static void link_time_slot(struct snd_dbri * dbri, int pipe,
                            int prevpipe, int nextpipe,
                            int length, int cycle)
@@ -920,6 +931,10 @@ static void link_time_slot(struct snd_dbri * dbri, int pipe,
         dbri_cmdsend(dbri, cmd, 4);
 }
 
+#if 0
+/*
+ * Lock must be held before calling this.
+ */
 static void unlink_time_slot(struct snd_dbri * dbri, int pipe,
                              enum in_or_out direction, int prevpipe,
                              int nextpipe)
@@ -952,6 +967,7 @@ static void unlink_time_slot(struct snd_dbri * dbri, int pipe,
 
         dbri_cmdsend(dbri, cmd, 4);
 }
+#endif
 
 /* xmit_fixed() / recv_fixed()
  *
@@ -965,11 +981,14 @@ static void unlink_time_slot(struct snd_dbri * dbri, int pipe,
  * the actual time slot is.  The interrupt handler takes care of bit
  * ordering and alignment.  An 8-bit time slot will always end up
  * in the low-order 8 bits, filled either MSB-first or LSB-first,
- * depending on the settings passed to setup_pipe()
+ * depending on the settings passed to setup_pipe().
+ *
+ * Lock must not be held before calling it.
  */
 static void xmit_fixed(struct snd_dbri * dbri, int pipe, unsigned int data)
 {
         s32 *cmd;
+        unsigned long flags;
 
         if (pipe < 16 || pipe > DBRI_MAX_PIPE) {
                 printk(KERN_ERR "DBRI: xmit_fixed: Illegal pipe number\n");
@@ -1002,8 +1021,11 @@ static void xmit_fixed(struct snd_dbri * dbri, int pipe, unsigned int data)
         *(cmd++) = data;
         *(cmd++) = DBRI_CMD(D_PAUSE, 0, 0);
 
+        spin_lock_irqsave(&dbri->lock, flags);
         dbri_cmdsend(dbri, cmd, 3);
+        spin_unlock_irqrestore(&dbri->lock, flags);
         dbri_cmdwait(dbri);
+
 }
 
 static void recv_fixed(struct snd_dbri * dbri, int pipe, volatile __u32 * ptr)
@@ -1039,6 +1061,8 @@ static void recv_fixed(struct snd_dbri * dbri, int pipe, volatile __u32 * ptr)
  * be spread across multiple descriptors.
  *
  * All descriptors create a ring buffer.
+ *
+ * Lock must be held before calling this.
  */
 static int setup_descs(struct snd_dbri * dbri, int streamno, unsigned int period)
 {
@@ -1186,6 +1210,9 @@ multiplexed serial interface which the DBRI can operate in either master
 
 enum master_or_slave { CHImaster, CHIslave };
 
+/*
+ * Lock must not be held before calling it.
+ */
 static void reset_chi(struct snd_dbri * dbri, enum master_or_slave master_or_slave,
                       int bits_per_frame)
 {
@@ -1258,9 +1285,14 @@ static void reset_chi(struct snd_dbri * dbri, enum master_or_slave master_or_sla
 In the standard SPARC audio configuration, the CS4215 codec is attached
 to the DBRI via the CHI interface and few of the DBRI's PIO pins.
 
+ * Lock must not be held before calling it.
+
 */
 static void cs4215_setup_pipes(struct snd_dbri * dbri)
 {
+        unsigned long flags;
+
+        spin_lock_irqsave(&dbri->lock, flags);
         /*
          * Data mode:
          * Pipe  4: Send timeslots 1-4 (audio data)
@@ -1284,6 +1316,7 @@ static void cs4215_setup_pipes(struct snd_dbri * dbri)
         setup_pipe(dbri, 17, D_SDP_FIXED | D_SDP_TO_SER | D_SDP_MSB);
         setup_pipe(dbri, 18, D_SDP_FIXED | D_SDP_FROM_SER | D_SDP_MSB);
         setup_pipe(dbri, 19, D_SDP_FIXED | D_SDP_FROM_SER | D_SDP_MSB);
+        spin_unlock_irqrestore(&dbri->lock, flags);
 
         dbri_cmdwait(dbri);
 }
@@ -1358,6 +1391,7 @@ static void cs4215_open(struct snd_dbri * dbri)
 {
         int data_width;
         u32 tmp;
+        unsigned long flags;
 
         dprintk(D_MM, "cs4215_open: %d channels, %d bits\n",
                 dbri->mm.channels, dbri->mm.precision);
@@ -1382,6 +1416,7 @@ static void cs4215_open(struct snd_dbri * dbri)
          * bits.  The CS4215, it seems, observes TSIN (the delayed signal)
          * even if it's the CHI master.  Don't ask me...
          */
+        spin_lock_irqsave(&dbri->lock, flags);
         tmp = sbus_readl(dbri->regs + REG0);
         tmp &= ~(D_C);          /* Disable CHI */
         sbus_writel(tmp, dbri->regs + REG0);
@@ -1409,6 +1444,7 @@ static void cs4215_open(struct snd_dbri * dbri)
         tmp = sbus_readl(dbri->regs + REG0);
         tmp |= D_C;             /* Enable CHI */
         sbus_writel(tmp, dbri->regs + REG0);
+        spin_unlock_irqrestore(&dbri->lock, flags);
 
         cs4215_setdata(dbri, 0);
 }
@@ -1420,6 +1456,7 @@ static int cs4215_setctrl(struct snd_dbri * dbri)
 {
         int i, val;
         u32 tmp;
+        unsigned long flags;
 
         /* FIXME - let the CPU do something useful during these delays */
 
@@ -1456,6 +1493,7 @@ static int cs4215_setctrl(struct snd_dbri * dbri)
          * done in hardware by a TI 248 that delays the DBRI->4215
          * frame sync signal by eight clock cycles.  Anybody know why?
          */
+        spin_lock_irqsave(&dbri->lock, flags);
         tmp = sbus_readl(dbri->regs + REG0);
         tmp &= ~D_C;            /* Disable CHI */
         sbus_writel(tmp, dbri->regs + REG0);
@@ -1472,14 +1510,17 @@ static int cs4215_setctrl(struct snd_dbri * dbri)
         link_time_slot(dbri, 17, 16, 16, 32, dbri->mm.offset);
         link_time_slot(dbri, 18, 16, 16, 8, dbri->mm.offset);
         link_time_slot(dbri, 19, 18, 16, 8, dbri->mm.offset + 48);
+        spin_unlock_irqrestore(&dbri->lock, flags);
 
         /* Wait for the chip to echo back CLB (Control Latch Bit) as zero */
         dbri->mm.ctrl[0] &= ~CS4215_CLB;
         xmit_fixed(dbri, 17, *(int *)dbri->mm.ctrl);
 
+        spin_lock_irqsave(&dbri->lock, flags);
         tmp = sbus_readl(dbri->regs + REG0);
         tmp |= D_C;             /* Enable CHI */
         sbus_writel(tmp, dbri->regs + REG0);
+        spin_unlock_irqrestore(&dbri->lock, flags);
 
         for (i = 10; ((dbri->mm.status & 0xe4) != 0x20); --i) {
                 msleep_interruptible(1);
@@ -1688,6 +1729,7 @@ static void xmit_descs(struct snd_dbri *dbri)
                         dbri->pipes[info->pipe].desc = first_td;
                 }
         }
+
         spin_unlock_irqrestore(&dbri->lock, flags);
 }
 
@@ -2093,7 +2135,6 @@ static int snd_dbri_prepare(struct snd_pcm_substream *substream)
 {
         struct snd_dbri *dbri = snd_pcm_substream_chip(substream);
         struct dbri_streaminfo *info = DBRI_STREAM(dbri, substream);
-        struct snd_pcm_runtime *runtime = substream->runtime;
         int ret;
 
         info->size = snd_pcm_lib_buffer_bytes(substream);
@@ -2232,7 +2273,6 @@ static int snd_cs4215_put_volume(struct snd_kcontrol *kcontrol,
 {
         struct snd_dbri *dbri = snd_kcontrol_chip(kcontrol);
         struct dbri_streaminfo *info = &dbri->stream_info[kcontrol->private_value];
-        unsigned long flags;
         int changed = 0;
 
         if (info->left_gain != ucontrol->value.integer.value[0]) {
@@ -2247,13 +2287,9 @@ static int snd_cs4215_put_volume(struct snd_kcontrol *kcontrol,
                 /* First mute outputs, and wait 1/8000 sec (125 us)
                  * to make sure this takes.  This avoids clicking noises.
                  */
-                spin_lock_irqsave(&dbri->lock, flags);
-
                 cs4215_setdata(dbri, 1);
                 udelay(125);
                 cs4215_setdata(dbri, 0);
-
-                spin_unlock_irqrestore(&dbri->lock, flags);
         }
         return changed;
 }
@@ -2300,7 +2336,6 @@ static int snd_cs4215_put_single(struct snd_kcontrol *kcontrol,
                                  struct snd_ctl_elem_value *ucontrol)
 {
         struct snd_dbri *dbri = snd_kcontrol_chip(kcontrol);
-        unsigned long flags;
         int elem = kcontrol->private_value & 0xff;
         int shift = (kcontrol->private_value >> 8) & 0xff;
         int mask = (kcontrol->private_value >> 16) & 0xff;
@@ -2333,13 +2368,9 @@ static int snd_cs4215_put_single(struct snd_kcontrol *kcontrol,
                 /* First mute outputs, and wait 1/8000 sec (125 us)
                  * to make sure this takes.  This avoids clicking noises.
                  */
-                spin_lock_irqsave(&dbri->lock, flags);
-
                 cs4215_setdata(dbri, 1);
                 udelay(125);
                 cs4215_setdata(dbri, 0);
-
-                spin_unlock_irqrestore(&dbri->lock, flags);
         }
         return changed;
 }