Mike Isely | d855497 | 2006-06-26 20:58:46 -0300 | [diff] [blame] | 1 | /* |
| 2 | * |
Mike Isely | d855497 | 2006-06-26 20:58:46 -0300 | [diff] [blame] | 3 | * |
| 4 | * Copyright (C) 2005 Mike Isely <isely@pobox.com> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License as published by |
| 8 | * the Free Software Foundation; either version 2 of the License |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program; if not, write to the Free Software |
| 17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 18 | * |
| 19 | */ |
| 20 | |
| 21 | #include "pvrusb2-ioread.h" |
| 22 | #include "pvrusb2-debug.h" |
| 23 | #include <linux/errno.h> |
| 24 | #include <linux/string.h> |
Andrea Righi | 27ac792 | 2008-07-23 21:28:13 -0700 | [diff] [blame] | 25 | #include <linux/mm.h> |
Mike Isely | d855497 | 2006-06-26 20:58:46 -0300 | [diff] [blame] | 26 | #include <linux/slab.h> |
| 27 | #include <linux/mutex.h> |
| 28 | #include <asm/uaccess.h> |
| 29 | |
| 30 | #define BUFFER_COUNT 32 |
| 31 | #define BUFFER_SIZE PAGE_ALIGN(0x4000) |
| 32 | |
| 33 | struct pvr2_ioread { |
| 34 | struct pvr2_stream *stream; |
| 35 | char *buffer_storage[BUFFER_COUNT]; |
| 36 | char *sync_key_ptr; |
| 37 | unsigned int sync_key_len; |
| 38 | unsigned int sync_buf_offs; |
| 39 | unsigned int sync_state; |
| 40 | unsigned int sync_trashed_count; |
| 41 | int enabled; // Streaming is on |
| 42 | int spigot_open; // OK to pass data to client |
| 43 | int stream_running; // Passing data to client now |
| 44 | |
| 45 | /* State relevant to current buffer being read */ |
| 46 | struct pvr2_buffer *c_buf; |
| 47 | char *c_data_ptr; |
| 48 | unsigned int c_data_len; |
| 49 | unsigned int c_data_offs; |
| 50 | struct mutex mutex; |
| 51 | }; |
| 52 | |
| 53 | static int pvr2_ioread_init(struct pvr2_ioread *cp) |
| 54 | { |
| 55 | unsigned int idx; |
| 56 | |
Mike Isely | a0fd1cb | 2006-06-30 11:35:28 -0300 | [diff] [blame] | 57 | cp->stream = NULL; |
Mike Isely | d855497 | 2006-06-26 20:58:46 -0300 | [diff] [blame] | 58 | mutex_init(&cp->mutex); |
| 59 | |
| 60 | for (idx = 0; idx < BUFFER_COUNT; idx++) { |
| 61 | cp->buffer_storage[idx] = kmalloc(BUFFER_SIZE,GFP_KERNEL); |
| 62 | if (!(cp->buffer_storage[idx])) break; |
| 63 | } |
| 64 | |
| 65 | if (idx < BUFFER_COUNT) { |
| 66 | // An allocation appears to have failed |
| 67 | for (idx = 0; idx < BUFFER_COUNT; idx++) { |
| 68 | if (!(cp->buffer_storage[idx])) continue; |
| 69 | kfree(cp->buffer_storage[idx]); |
| 70 | } |
| 71 | return -ENOMEM; |
| 72 | } |
| 73 | return 0; |
| 74 | } |
| 75 | |
| 76 | static void pvr2_ioread_done(struct pvr2_ioread *cp) |
| 77 | { |
| 78 | unsigned int idx; |
| 79 | |
Mike Isely | a0fd1cb | 2006-06-30 11:35:28 -0300 | [diff] [blame] | 80 | pvr2_ioread_setup(cp,NULL); |
Mike Isely | d855497 | 2006-06-26 20:58:46 -0300 | [diff] [blame] | 81 | for (idx = 0; idx < BUFFER_COUNT; idx++) { |
| 82 | if (!(cp->buffer_storage[idx])) continue; |
| 83 | kfree(cp->buffer_storage[idx]); |
| 84 | } |
| 85 | } |
| 86 | |
| 87 | struct pvr2_ioread *pvr2_ioread_create(void) |
| 88 | { |
| 89 | struct pvr2_ioread *cp; |
Mike Isely | ca545f7 | 2007-01-20 00:37:11 -0300 | [diff] [blame] | 90 | cp = kzalloc(sizeof(*cp),GFP_KERNEL); |
Mike Isely | a0fd1cb | 2006-06-30 11:35:28 -0300 | [diff] [blame] | 91 | if (!cp) return NULL; |
Mike Isely | d855497 | 2006-06-26 20:58:46 -0300 | [diff] [blame] | 92 | pvr2_trace(PVR2_TRACE_STRUCT,"pvr2_ioread_create id=%p",cp); |
Mike Isely | d855497 | 2006-06-26 20:58:46 -0300 | [diff] [blame] | 93 | if (pvr2_ioread_init(cp) < 0) { |
| 94 | kfree(cp); |
Mike Isely | a0fd1cb | 2006-06-30 11:35:28 -0300 | [diff] [blame] | 95 | return NULL; |
Mike Isely | d855497 | 2006-06-26 20:58:46 -0300 | [diff] [blame] | 96 | } |
| 97 | return cp; |
| 98 | } |
| 99 | |
| 100 | void pvr2_ioread_destroy(struct pvr2_ioread *cp) |
| 101 | { |
| 102 | if (!cp) return; |
| 103 | pvr2_ioread_done(cp); |
| 104 | pvr2_trace(PVR2_TRACE_STRUCT,"pvr2_ioread_destroy id=%p",cp); |
| 105 | if (cp->sync_key_ptr) { |
| 106 | kfree(cp->sync_key_ptr); |
Mike Isely | a0fd1cb | 2006-06-30 11:35:28 -0300 | [diff] [blame] | 107 | cp->sync_key_ptr = NULL; |
Mike Isely | d855497 | 2006-06-26 20:58:46 -0300 | [diff] [blame] | 108 | } |
| 109 | kfree(cp); |
| 110 | } |
| 111 | |
| 112 | void pvr2_ioread_set_sync_key(struct pvr2_ioread *cp, |
| 113 | const char *sync_key_ptr, |
| 114 | unsigned int sync_key_len) |
| 115 | { |
| 116 | if (!cp) return; |
| 117 | |
| 118 | if (!sync_key_ptr) sync_key_len = 0; |
| 119 | if ((sync_key_len == cp->sync_key_len) && |
| 120 | ((!sync_key_len) || |
| 121 | (!memcmp(sync_key_ptr,cp->sync_key_ptr,sync_key_len)))) return; |
| 122 | |
| 123 | if (sync_key_len != cp->sync_key_len) { |
| 124 | if (cp->sync_key_ptr) { |
| 125 | kfree(cp->sync_key_ptr); |
Mike Isely | a0fd1cb | 2006-06-30 11:35:28 -0300 | [diff] [blame] | 126 | cp->sync_key_ptr = NULL; |
Mike Isely | d855497 | 2006-06-26 20:58:46 -0300 | [diff] [blame] | 127 | } |
| 128 | cp->sync_key_len = 0; |
| 129 | if (sync_key_len) { |
| 130 | cp->sync_key_ptr = kmalloc(sync_key_len,GFP_KERNEL); |
| 131 | if (cp->sync_key_ptr) { |
| 132 | cp->sync_key_len = sync_key_len; |
| 133 | } |
| 134 | } |
| 135 | } |
| 136 | if (!cp->sync_key_len) return; |
| 137 | memcpy(cp->sync_key_ptr,sync_key_ptr,cp->sync_key_len); |
| 138 | } |
| 139 | |
| 140 | static void pvr2_ioread_stop(struct pvr2_ioread *cp) |
| 141 | { |
| 142 | if (!(cp->enabled)) return; |
| 143 | pvr2_trace(PVR2_TRACE_START_STOP, |
| 144 | "/*---TRACE_READ---*/ pvr2_ioread_stop id=%p",cp); |
| 145 | pvr2_stream_kill(cp->stream); |
Mike Isely | a0fd1cb | 2006-06-30 11:35:28 -0300 | [diff] [blame] | 146 | cp->c_buf = NULL; |
| 147 | cp->c_data_ptr = NULL; |
Mike Isely | d855497 | 2006-06-26 20:58:46 -0300 | [diff] [blame] | 148 | cp->c_data_len = 0; |
| 149 | cp->c_data_offs = 0; |
| 150 | cp->enabled = 0; |
| 151 | cp->stream_running = 0; |
| 152 | cp->spigot_open = 0; |
| 153 | if (cp->sync_state) { |
| 154 | pvr2_trace(PVR2_TRACE_DATA_FLOW, |
| 155 | "/*---TRACE_READ---*/ sync_state <== 0"); |
| 156 | cp->sync_state = 0; |
| 157 | } |
| 158 | } |
| 159 | |
| 160 | static int pvr2_ioread_start(struct pvr2_ioread *cp) |
| 161 | { |
| 162 | int stat; |
| 163 | struct pvr2_buffer *bp; |
| 164 | if (cp->enabled) return 0; |
| 165 | if (!(cp->stream)) return 0; |
| 166 | pvr2_trace(PVR2_TRACE_START_STOP, |
| 167 | "/*---TRACE_READ---*/ pvr2_ioread_start id=%p",cp); |
Al Viro | 5fa1247 | 2008-03-29 03:07:38 +0000 | [diff] [blame] | 168 | while ((bp = pvr2_stream_get_idle_buffer(cp->stream)) != NULL) { |
Mike Isely | d855497 | 2006-06-26 20:58:46 -0300 | [diff] [blame] | 169 | stat = pvr2_buffer_queue(bp); |
| 170 | if (stat < 0) { |
| 171 | pvr2_trace(PVR2_TRACE_DATA_FLOW, |
| 172 | "/*---TRACE_READ---*/" |
| 173 | " pvr2_ioread_start id=%p" |
| 174 | " error=%d", |
| 175 | cp,stat); |
| 176 | pvr2_ioread_stop(cp); |
| 177 | return stat; |
| 178 | } |
| 179 | } |
| 180 | cp->enabled = !0; |
Mike Isely | a0fd1cb | 2006-06-30 11:35:28 -0300 | [diff] [blame] | 181 | cp->c_buf = NULL; |
| 182 | cp->c_data_ptr = NULL; |
Mike Isely | d855497 | 2006-06-26 20:58:46 -0300 | [diff] [blame] | 183 | cp->c_data_len = 0; |
| 184 | cp->c_data_offs = 0; |
| 185 | cp->stream_running = 0; |
| 186 | if (cp->sync_key_len) { |
| 187 | pvr2_trace(PVR2_TRACE_DATA_FLOW, |
| 188 | "/*---TRACE_READ---*/ sync_state <== 1"); |
| 189 | cp->sync_state = 1; |
| 190 | cp->sync_trashed_count = 0; |
| 191 | cp->sync_buf_offs = 0; |
| 192 | } |
| 193 | cp->spigot_open = 0; |
| 194 | return 0; |
| 195 | } |
| 196 | |
| 197 | struct pvr2_stream *pvr2_ioread_get_stream(struct pvr2_ioread *cp) |
| 198 | { |
| 199 | return cp->stream; |
| 200 | } |
| 201 | |
| 202 | int pvr2_ioread_setup(struct pvr2_ioread *cp,struct pvr2_stream *sp) |
| 203 | { |
| 204 | int ret; |
| 205 | unsigned int idx; |
| 206 | struct pvr2_buffer *bp; |
| 207 | |
| 208 | mutex_lock(&cp->mutex); do { |
| 209 | if (cp->stream) { |
| 210 | pvr2_trace(PVR2_TRACE_START_STOP, |
| 211 | "/*---TRACE_READ---*/" |
| 212 | " pvr2_ioread_setup (tear-down) id=%p",cp); |
| 213 | pvr2_ioread_stop(cp); |
| 214 | pvr2_stream_kill(cp->stream); |
Mike Isely | e61b6fc | 2006-07-18 22:42:18 -0300 | [diff] [blame] | 215 | if (pvr2_stream_get_buffer_count(cp->stream)) { |
| 216 | pvr2_stream_set_buffer_count(cp->stream,0); |
| 217 | } |
Mike Isely | a0fd1cb | 2006-06-30 11:35:28 -0300 | [diff] [blame] | 218 | cp->stream = NULL; |
Mike Isely | d855497 | 2006-06-26 20:58:46 -0300 | [diff] [blame] | 219 | } |
| 220 | if (sp) { |
| 221 | pvr2_trace(PVR2_TRACE_START_STOP, |
| 222 | "/*---TRACE_READ---*/" |
| 223 | " pvr2_ioread_setup (setup) id=%p",cp); |
| 224 | pvr2_stream_kill(sp); |
| 225 | ret = pvr2_stream_set_buffer_count(sp,BUFFER_COUNT); |
| 226 | if (ret < 0) return ret; |
| 227 | for (idx = 0; idx < BUFFER_COUNT; idx++) { |
| 228 | bp = pvr2_stream_get_buffer(sp,idx); |
| 229 | pvr2_buffer_set_buffer(bp, |
| 230 | cp->buffer_storage[idx], |
| 231 | BUFFER_SIZE); |
| 232 | } |
| 233 | cp->stream = sp; |
| 234 | } |
| 235 | } while (0); mutex_unlock(&cp->mutex); |
| 236 | |
| 237 | return 0; |
| 238 | } |
| 239 | |
| 240 | int pvr2_ioread_set_enabled(struct pvr2_ioread *cp,int fl) |
| 241 | { |
| 242 | int ret = 0; |
| 243 | if ((!fl) == (!(cp->enabled))) return ret; |
| 244 | |
| 245 | mutex_lock(&cp->mutex); do { |
| 246 | if (fl) { |
| 247 | ret = pvr2_ioread_start(cp); |
| 248 | } else { |
| 249 | pvr2_ioread_stop(cp); |
| 250 | } |
| 251 | } while (0); mutex_unlock(&cp->mutex); |
| 252 | return ret; |
| 253 | } |
| 254 | |
Adrian Bunk | 07e337e | 2006-06-30 11:30:20 -0300 | [diff] [blame] | 255 | static int pvr2_ioread_get_buffer(struct pvr2_ioread *cp) |
Mike Isely | d855497 | 2006-06-26 20:58:46 -0300 | [diff] [blame] | 256 | { |
| 257 | int stat; |
| 258 | |
| 259 | while (cp->c_data_len <= cp->c_data_offs) { |
| 260 | if (cp->c_buf) { |
| 261 | // Flush out current buffer first. |
| 262 | stat = pvr2_buffer_queue(cp->c_buf); |
| 263 | if (stat < 0) { |
| 264 | // Streaming error... |
| 265 | pvr2_trace(PVR2_TRACE_DATA_FLOW, |
| 266 | "/*---TRACE_READ---*/" |
| 267 | " pvr2_ioread_read id=%p" |
| 268 | " queue_error=%d", |
| 269 | cp,stat); |
| 270 | pvr2_ioread_stop(cp); |
| 271 | return 0; |
| 272 | } |
Mike Isely | a0fd1cb | 2006-06-30 11:35:28 -0300 | [diff] [blame] | 273 | cp->c_buf = NULL; |
| 274 | cp->c_data_ptr = NULL; |
Mike Isely | d855497 | 2006-06-26 20:58:46 -0300 | [diff] [blame] | 275 | cp->c_data_len = 0; |
| 276 | cp->c_data_offs = 0; |
| 277 | } |
| 278 | // Now get a freshly filled buffer. |
| 279 | cp->c_buf = pvr2_stream_get_ready_buffer(cp->stream); |
| 280 | if (!cp->c_buf) break; // Nothing ready; done. |
| 281 | cp->c_data_len = pvr2_buffer_get_count(cp->c_buf); |
| 282 | if (!cp->c_data_len) { |
| 283 | // Nothing transferred. Was there an error? |
| 284 | stat = pvr2_buffer_get_status(cp->c_buf); |
| 285 | if (stat < 0) { |
| 286 | // Streaming error... |
| 287 | pvr2_trace(PVR2_TRACE_DATA_FLOW, |
| 288 | "/*---TRACE_READ---*/" |
| 289 | " pvr2_ioread_read id=%p" |
| 290 | " buffer_error=%d", |
| 291 | cp,stat); |
| 292 | pvr2_ioread_stop(cp); |
| 293 | // Give up. |
| 294 | return 0; |
| 295 | } |
| 296 | // Start over... |
| 297 | continue; |
| 298 | } |
| 299 | cp->c_data_offs = 0; |
| 300 | cp->c_data_ptr = cp->buffer_storage[ |
| 301 | pvr2_buffer_get_id(cp->c_buf)]; |
| 302 | } |
| 303 | return !0; |
| 304 | } |
| 305 | |
Adrian Bunk | 07e337e | 2006-06-30 11:30:20 -0300 | [diff] [blame] | 306 | static void pvr2_ioread_filter(struct pvr2_ioread *cp) |
Mike Isely | d855497 | 2006-06-26 20:58:46 -0300 | [diff] [blame] | 307 | { |
| 308 | unsigned int idx; |
| 309 | if (!cp->enabled) return; |
| 310 | if (cp->sync_state != 1) return; |
| 311 | |
| 312 | // Search the stream for our synchronization key. This is made |
| 313 | // complicated by the fact that in order to be honest with |
| 314 | // ourselves here we must search across buffer boundaries... |
| 315 | mutex_lock(&cp->mutex); while (1) { |
| 316 | // Ensure we have a buffer |
| 317 | if (!pvr2_ioread_get_buffer(cp)) break; |
| 318 | if (!cp->c_data_len) break; |
| 319 | |
| 320 | // Now walk the buffer contents until we match the key or |
| 321 | // run out of buffer data. |
| 322 | for (idx = cp->c_data_offs; idx < cp->c_data_len; idx++) { |
| 323 | if (cp->sync_buf_offs >= cp->sync_key_len) break; |
| 324 | if (cp->c_data_ptr[idx] == |
| 325 | cp->sync_key_ptr[cp->sync_buf_offs]) { |
| 326 | // Found the next key byte |
| 327 | (cp->sync_buf_offs)++; |
| 328 | } else { |
| 329 | // Whoops, mismatched. Start key over... |
| 330 | cp->sync_buf_offs = 0; |
| 331 | } |
| 332 | } |
| 333 | |
| 334 | // Consume what we've walked through |
| 335 | cp->c_data_offs += idx; |
| 336 | cp->sync_trashed_count += idx; |
| 337 | |
| 338 | // If we've found the key, then update state and get out. |
| 339 | if (cp->sync_buf_offs >= cp->sync_key_len) { |
| 340 | cp->sync_trashed_count -= cp->sync_key_len; |
| 341 | pvr2_trace(PVR2_TRACE_DATA_FLOW, |
| 342 | "/*---TRACE_READ---*/" |
| 343 | " sync_state <== 2 (skipped %u bytes)", |
| 344 | cp->sync_trashed_count); |
| 345 | cp->sync_state = 2; |
| 346 | cp->sync_buf_offs = 0; |
| 347 | break; |
| 348 | } |
| 349 | |
| 350 | if (cp->c_data_offs < cp->c_data_len) { |
| 351 | // Sanity check - should NEVER get here |
| 352 | pvr2_trace(PVR2_TRACE_ERROR_LEGS, |
| 353 | "ERROR: pvr2_ioread filter sync problem" |
| 354 | " len=%u offs=%u", |
| 355 | cp->c_data_len,cp->c_data_offs); |
| 356 | // Get out so we don't get stuck in an infinite |
| 357 | // loop. |
| 358 | break; |
| 359 | } |
| 360 | |
| 361 | continue; // (for clarity) |
| 362 | } mutex_unlock(&cp->mutex); |
| 363 | } |
| 364 | |
| 365 | int pvr2_ioread_avail(struct pvr2_ioread *cp) |
| 366 | { |
| 367 | int ret; |
| 368 | if (!(cp->enabled)) { |
| 369 | // Stream is not enabled; so this is an I/O error |
| 370 | return -EIO; |
| 371 | } |
| 372 | |
| 373 | if (cp->sync_state == 1) { |
| 374 | pvr2_ioread_filter(cp); |
| 375 | if (cp->sync_state == 1) return -EAGAIN; |
| 376 | } |
| 377 | |
| 378 | ret = 0; |
| 379 | if (cp->stream_running) { |
| 380 | if (!pvr2_stream_get_ready_count(cp->stream)) { |
| 381 | // No data available at all right now. |
| 382 | ret = -EAGAIN; |
| 383 | } |
| 384 | } else { |
| 385 | if (pvr2_stream_get_ready_count(cp->stream) < BUFFER_COUNT/2) { |
| 386 | // Haven't buffered up enough yet; try again later |
| 387 | ret = -EAGAIN; |
| 388 | } |
| 389 | } |
| 390 | |
| 391 | if ((!(cp->spigot_open)) != (!(ret == 0))) { |
| 392 | cp->spigot_open = (ret == 0); |
| 393 | pvr2_trace(PVR2_TRACE_DATA_FLOW, |
| 394 | "/*---TRACE_READ---*/ data is %s", |
| 395 | cp->spigot_open ? "available" : "pending"); |
| 396 | } |
| 397 | |
| 398 | return ret; |
| 399 | } |
| 400 | |
| 401 | int pvr2_ioread_read(struct pvr2_ioread *cp,void __user *buf,unsigned int cnt) |
| 402 | { |
| 403 | unsigned int copied_cnt; |
| 404 | unsigned int bcnt; |
| 405 | const char *src; |
| 406 | int stat; |
| 407 | int ret = 0; |
| 408 | unsigned int req_cnt = cnt; |
| 409 | |
| 410 | if (!cnt) { |
| 411 | pvr2_trace(PVR2_TRACE_TRAP, |
| 412 | "/*---TRACE_READ---*/ pvr2_ioread_read id=%p" |
| 413 | " ZERO Request? Returning zero.",cp); |
| 414 | return 0; |
| 415 | } |
| 416 | |
| 417 | stat = pvr2_ioread_avail(cp); |
| 418 | if (stat < 0) return stat; |
| 419 | |
| 420 | cp->stream_running = !0; |
| 421 | |
| 422 | mutex_lock(&cp->mutex); do { |
| 423 | |
| 424 | // Suck data out of the buffers and copy to the user |
| 425 | copied_cnt = 0; |
| 426 | if (!buf) cnt = 0; |
| 427 | while (1) { |
| 428 | if (!pvr2_ioread_get_buffer(cp)) { |
| 429 | ret = -EIO; |
| 430 | break; |
| 431 | } |
| 432 | |
| 433 | if (!cnt) break; |
| 434 | |
| 435 | if (cp->sync_state == 2) { |
| 436 | // We're repeating the sync key data into |
| 437 | // the stream. |
| 438 | src = cp->sync_key_ptr + cp->sync_buf_offs; |
| 439 | bcnt = cp->sync_key_len - cp->sync_buf_offs; |
| 440 | } else { |
| 441 | // Normal buffer copy |
| 442 | src = cp->c_data_ptr + cp->c_data_offs; |
| 443 | bcnt = cp->c_data_len - cp->c_data_offs; |
| 444 | } |
| 445 | |
| 446 | if (!bcnt) break; |
| 447 | |
| 448 | // Don't run past user's buffer |
| 449 | if (bcnt > cnt) bcnt = cnt; |
| 450 | |
| 451 | if (copy_to_user(buf,src,bcnt)) { |
| 452 | // User supplied a bad pointer? |
| 453 | // Give up - this *will* cause data |
| 454 | // to be lost. |
| 455 | ret = -EFAULT; |
| 456 | break; |
| 457 | } |
| 458 | cnt -= bcnt; |
| 459 | buf += bcnt; |
| 460 | copied_cnt += bcnt; |
| 461 | |
| 462 | if (cp->sync_state == 2) { |
| 463 | // Update offset inside sync key that we're |
| 464 | // repeating back out. |
| 465 | cp->sync_buf_offs += bcnt; |
| 466 | if (cp->sync_buf_offs >= cp->sync_key_len) { |
| 467 | // Consumed entire key; switch mode |
| 468 | // to normal. |
| 469 | pvr2_trace(PVR2_TRACE_DATA_FLOW, |
| 470 | "/*---TRACE_READ---*/" |
| 471 | " sync_state <== 0"); |
| 472 | cp->sync_state = 0; |
| 473 | } |
| 474 | } else { |
| 475 | // Update buffer offset. |
| 476 | cp->c_data_offs += bcnt; |
| 477 | } |
| 478 | } |
| 479 | |
| 480 | } while (0); mutex_unlock(&cp->mutex); |
| 481 | |
| 482 | if (!ret) { |
| 483 | if (copied_cnt) { |
| 484 | // If anything was copied, return that count |
| 485 | ret = copied_cnt; |
| 486 | } else { |
| 487 | // Nothing copied; suggest to caller that another |
| 488 | // attempt should be tried again later |
| 489 | ret = -EAGAIN; |
| 490 | } |
| 491 | } |
| 492 | |
| 493 | pvr2_trace(PVR2_TRACE_DATA_FLOW, |
| 494 | "/*---TRACE_READ---*/ pvr2_ioread_read" |
| 495 | " id=%p request=%d result=%d", |
| 496 | cp,req_cnt,ret); |
| 497 | return ret; |
| 498 | } |
| 499 | |
| 500 | |
| 501 | /* |
| 502 | Stuff for Emacs to see, in order to encourage consistent editing style: |
| 503 | *** Local Variables: *** |
| 504 | *** mode: c *** |
| 505 | *** fill-column: 75 *** |
| 506 | *** tab-width: 8 *** |
| 507 | *** c-basic-offset: 8 *** |
| 508 | *** End: *** |
| 509 | */ |