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path: root/drivers/dma/ipu/ipu_idmac.c
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Diffstat (limited to 'drivers/dma/ipu/ipu_idmac.c')
-rw-r--r--drivers/dma/ipu/ipu_idmac.c50
1 files changed, 0 insertions, 50 deletions
diff --git a/drivers/dma/ipu/ipu_idmac.c b/drivers/dma/ipu/ipu_idmac.c
index cb26ee9773d6..c1a125e7d1df 100644
--- a/drivers/dma/ipu/ipu_idmac.c
+++ b/drivers/dma/ipu/ipu_idmac.c
@@ -1145,29 +1145,6 @@ static int ipu_disable_channel(struct idmac *idmac, struct idmac_channel *ichan,
1145 reg = idmac_read_icreg(ipu, IDMAC_CHA_EN); 1145 reg = idmac_read_icreg(ipu, IDMAC_CHA_EN);
1146 idmac_write_icreg(ipu, reg & ~chan_mask, IDMAC_CHA_EN); 1146 idmac_write_icreg(ipu, reg & ~chan_mask, IDMAC_CHA_EN);
1147 1147
1148 /*
1149 * Problem (observed with channel DMAIC_7): after enabling the channel
1150 * and initialising buffers, there comes an interrupt with current still
1151 * pointing at buffer 0, whereas it should use buffer 0 first and only
1152 * generate an interrupt when it is done, then current should already
1153 * point to buffer 1. This spurious interrupt also comes on channel
1154 * DMASDC_0. With DMAIC_7 normally, is we just leave the ISR after the
1155 * first interrupt, there comes the second with current correctly
1156 * pointing to buffer 1 this time. But sometimes this second interrupt
1157 * doesn't come and the channel hangs. Clearing BUFx_RDY when disabling
1158 * the channel seems to prevent the channel from hanging, but it doesn't
1159 * prevent the spurious interrupt. This might also be unsafe. Think
1160 * about the IDMAC controller trying to switch to a buffer, when we
1161 * clear the ready bit, and re-enable it a moment later.
1162 */
1163 reg = idmac_read_ipureg(ipu, IPU_CHA_BUF0_RDY);
1164 idmac_write_ipureg(ipu, 0, IPU_CHA_BUF0_RDY);
1165 idmac_write_ipureg(ipu, reg & ~(1UL << channel), IPU_CHA_BUF0_RDY);
1166
1167 reg = idmac_read_ipureg(ipu, IPU_CHA_BUF1_RDY);
1168 idmac_write_ipureg(ipu, 0, IPU_CHA_BUF1_RDY);
1169 idmac_write_ipureg(ipu, reg & ~(1UL << channel), IPU_CHA_BUF1_RDY);
1170
1171 spin_unlock_irqrestore(&ipu->lock, flags); 1148 spin_unlock_irqrestore(&ipu->lock, flags);
1172 1149
1173 return 0; 1150 return 0;
@@ -1246,33 +1223,6 @@ static irqreturn_t idmac_interrupt(int irq, void *dev_id)
1246 1223
1247 /* Other interrupts do not interfere with this channel */ 1224 /* Other interrupts do not interfere with this channel */
1248 spin_lock(&ichan->lock); 1225 spin_lock(&ichan->lock);
1249 if (unlikely(chan_id != IDMAC_SDC_0 && chan_id != IDMAC_SDC_1 &&
1250 ((curbuf >> chan_id) & 1) == ichan->active_buffer &&
1251 !list_is_last(ichan->queue.next, &ichan->queue))) {
1252 int i = 100;
1253
1254 /* This doesn't help. See comment in ipu_disable_channel() */
1255 while (--i) {
1256 curbuf = idmac_read_ipureg(&ipu_data, IPU_CHA_CUR_BUF);
1257 if (((curbuf >> chan_id) & 1) != ichan->active_buffer)
1258 break;
1259 cpu_relax();
1260 }
1261
1262 if (!i) {
1263 spin_unlock(&ichan->lock);
1264 dev_dbg(dev,
1265 "IRQ on active buffer on channel %x, active "
1266 "%d, ready %x, %x, current %x!\n", chan_id,
1267 ichan->active_buffer, ready0, ready1, curbuf);
1268 return IRQ_NONE;
1269 } else
1270 dev_dbg(dev,
1271 "Buffer deactivated on channel %x, active "
1272 "%d, ready %x, %x, current %x, rest %d!\n", chan_id,
1273 ichan->active_buffer, ready0, ready1, curbuf, i);
1274 }
1275
1276 if (unlikely((ichan->active_buffer && (ready1 >> chan_id) & 1) || 1226 if (unlikely((ichan->active_buffer && (ready1 >> chan_id) & 1) ||
1277 (!ichan->active_buffer && (ready0 >> chan_id) & 1) 1227 (!ichan->active_buffer && (ready0 >> chan_id) & 1)
1278 )) { 1228 )) {