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authorClemens Ladisch <clemens@ladisch.de>2011-05-16 08:10:10 +0200
committerStefan Richter <stefanr@s5r6.in-berlin.de>2011-06-02 13:58:33 +0200
commitdd6254e5c0efe01ad255188898cb3dadf98cb56d (patch)
tree3417d788024a41ad5f28689fc1ef5095ae2a4b7f /drivers/firewire
parentbf337b15c28ae25904a73e7e2e0de2f9c4f0e9f8 (diff)
downloadlinux-dd6254e5c0efe01ad255188898cb3dadf98cb56d.tar.bz2
firewire: ohci: remove superfluous posted write flushes
The call to flush_writes() in context_stop() is superfluous because another register read is done immediately afterwards. The call to flush_writes() in ar_context_run() does not need to be done individually for each AR context, so move it to ohci_enable(). This also makes ohci_enable() clearer because it no longer depends on a side effect of ar_context_run() to flush its own register writes. Finally, the setting of a context's wake bit does not need to be flushed because neither the driver logic nor the API require the CPU to wait for this action. This removes the last MMIO reads from the packet queueing code paths. Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Diffstat (limited to 'drivers/firewire')
-rw-r--r--drivers/firewire/ohci.c14
1 files changed, 5 insertions, 9 deletions
diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index 438e6c831170..e291edaa5eef 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -629,7 +629,6 @@ static void ar_context_link_page(struct ar_context *ctx, unsigned int index)
ctx->last_buffer_index = index;
reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
- flush_writes(ctx->ohci);
}
static void ar_context_release(struct ar_context *ctx)
@@ -1001,7 +1000,6 @@ static void ar_context_run(struct ar_context *ctx)
reg_write(ctx->ohci, COMMAND_PTR(ctx->regs), ctx->descriptors_bus | 1);
reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_RUN);
- flush_writes(ctx->ohci);
}
static struct descriptor *find_branch_descriptor(struct descriptor *d, int z)
@@ -1201,7 +1199,6 @@ static void context_stop(struct context *ctx)
reg_write(ctx->ohci, CONTROL_CLEAR(ctx->regs), CONTEXT_RUN);
ctx->running = false;
- flush_writes(ctx->ohci);
for (i = 0; i < 10; i++) {
reg = reg_read(ctx->ohci, CONTROL_SET(ctx->regs));
@@ -1345,12 +1342,10 @@ static int at_context_queue_packet(struct context *ctx,
context_append(ctx, d, z, 4 - z);
- if (ctx->running) {
+ if (ctx->running)
reg_write(ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
- flush_writes(ohci);
- } else {
+ else
context_run(ctx, 0);
- }
return 0;
}
@@ -2196,7 +2191,9 @@ static int ohci_enable(struct fw_card *card,
OHCI1394_LinkControl_rcvPhyPkt);
ar_context_run(&ohci->ar_request_ctx);
- ar_context_run(&ohci->ar_response_ctx); /* also flushes writes */
+ ar_context_run(&ohci->ar_response_ctx);
+
+ flush_writes(ohci);
/* We are ready to go, reset bus to finish initialization. */
fw_schedule_bus_reset(&ohci->card, false, true);
@@ -3128,7 +3125,6 @@ static void ohci_flush_queue_iso(struct fw_iso_context *base)
&container_of(base, struct iso_context, base)->context;
reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
- flush_writes(ctx->ohci);
}
static const struct fw_card_driver ohci_driver = {