Eric Lee / linux-smarc-t335x-v3.2

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Commit 386a4153a2c1455e424f280d636efa3c91864466

Authored by Clemens Ladisch
Committed by Stefan Richter
1 parent 78dec56d6a
Exists in master and in 4 other branches v3.2_AM335xPSP_04.06.00.11, v3.2_NEWT335xPSP_04.06.00.11, v3.2_SBC_SMARTMEN, v3.2_SMARCT335xPSP_04.06.00.11

firewire: ohci: cache the context run bit 

The DMA context run control bit is entirely controlled by software, so
it is safe to cache it.  This allows the driver to avoid doing an
additional MMIO read when queueing an AT packet.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

Showing 1 changed file with 4 additions and 4 deletions Side-by-side Diff

drivers/firewire/ohci.c
Diff comments   View file @ 386a415
... ... @@ -125,6 +125,7 @@
125 125 struct fw_ohci *ohci;
126 126 u32 regs;
127 127 int total_allocation;
  128 + bool running;
128 129 bool flushing;
129 130  
130 131 /*
... ... @@ -1174,6 +1175,7 @@
1174 1175 le32_to_cpu(ctx->last->branch_address));
1175 1176 reg_write(ohci, CONTROL_CLEAR(ctx->regs), ~0);
1176 1177 reg_write(ohci, CONTROL_SET(ctx->regs), CONTEXT_RUN | extra);
  1178 + ctx->running = true;
1177 1179 flush_writes(ohci);
1178 1180 }
1179 1181  
... ... @@ -1202,6 +1204,7 @@
1202 1204  
1203 1205 ctx->active = false;
1204 1206 reg_write(ctx->ohci, CONTROL_CLEAR(ctx->regs), CONTEXT_RUN);
  1207 + ctx->running = false;
1205 1208 flush_writes(ctx->ohci);
1206 1209  
1207 1210 for (i = 0; i < 10; i++) {
... ... @@ -1232,7 +1235,6 @@
1232 1235 struct descriptor *d, *last;
1233 1236 __le32 *header;
1234 1237 int z, tcode;
1235   - u32 reg;
1236 1238  
1237 1239 d = context_get_descriptors(ctx, 4, &d_bus);
1238 1240 if (d == NULL) {
... ... @@ -1351,9 +1353,7 @@
1351 1353  
1352 1354 context_append(ctx, d, z, 4 - z);
1353 1355  
1354   - /* If the context isn't already running, start it up. */
1355   - reg = reg_read(ctx->ohci, CONTROL_SET(ctx->regs));
1356   - if ((reg & CONTEXT_RUN) == 0)
  1356 + if (!ctx->running)
1357 1357 context_run(ctx, 0);
1358 1358  
1359 1359 return 0;