On Tue, Jun 12, 2018 at 02:12:46PM -0500, Pierre-Louis Bossart wrote:
On 06/12/2018 05:53 AM, Shreyas NC wrote:
From: Vinod Koul vkoul@kernel.org
For each SoundWire stream operation, we need to parse master list and operate upon all master runtime.
This patch does the boilerplate conversion of stream handling from single master runtime to handle a list of master runtime.
Signed-off-by: Sanyog Kale sanyog.r.kale@intel.com Signed-off-by: Vinod Koul vkoul@kernel.org Signed-off-by: Shreyas NC shreyas.nc@intel.com
drivers/soundwire/stream.c | 308 +++++++++++++++++++++++++----------------- include/linux/soundwire/sdw.h | 2 - 2 files changed, 185 insertions(+), 125 deletions(-)
diff --git a/drivers/soundwire/stream.c b/drivers/soundwire/stream.c index eb942c6..36506a7 100644 --- a/drivers/soundwire/stream.c +++ b/drivers/soundwire/stream.c @@ -681,35 +681,44 @@ static int sdw_bank_switch(struct sdw_bus *bus) static int do_bank_switch(struct sdw_stream_runtime *stream) {
- struct sdw_master_runtime *m_rt = stream->m_rt;
- struct sdw_master_runtime *m_rt = NULL; const struct sdw_master_ops *ops;
- struct sdw_bus *bus = m_rt->bus;
- struct sdw_bus *bus = NULL; int ret = 0;
- ops = bus->ops;
- /* Pre-bank switch */
- if (ops->pre_bank_switch) {
ret = ops->pre_bank_switch(bus);
- list_for_each_entry(m_rt, &stream->master_list, stream_node) {
bus = m_rt->bus;ops = bus->ops;/* Pre-bank switch */if (ops->pre_bank_switch) {ret = ops->pre_bank_switch(bus);if (ret < 0) {dev_err(bus->dev,"Pre bank switch op failed: %d", ret);return ret;}}/* Bank switch */ret = sdw_bank_switch(bus);
dev_err(bus->dev, "Pre bank switch op failed: %d", ret);
dev_err(bus->dev, "Bank switch failed: %d", ret); return ret;You probably want to add a comment that in multi-link operation the actual bank_switch happens later and is done in a synchronized manner. This is lost if you just move code around and move the bank_switch into a loop.
I am actually no longer clear just looking at this code on when the bank_switch happens (i know we've discussed this before but I am trying to find out just based on this v2 instead of projecting how I think it should work): In Patch 6/6 it's pretty obvious that the bank switch happens when the SyncGO bit is set, but there is no comment or explanation on how we reach the intel_post_bank_switch() routine once for all masters handling a stream when everything is based on loops. Clearly the intel_pre_bank_switch is called multiple times (once per master), I guess I am missing what the trigger is for the intel_post_bank_switch() routine to be invoked?
Hi Pierre,
To answer your last question, do_bank_switch is where we perform all the bank switch operations.
In first loop for Master(s) involved in stream, ops->pre_bank_switch and bank_switch is performed. In 2nd loop for Master(s) involved in stream, ops->post_bank_switch and wait for bank switch is performed.
Assuming a stream with Master 1 and Master 2, the go_sync bit will be set in Master 1 intel_post_bank_switch call which will trigger bank switch for both the Master's. The Master 2 intel_post_bank_switch call will just return as it will won't see CMDSYNC bit set for any Master(s).
}
- /* Bank switch */
- ret = sdw_bank_switch(bus);
- if (ret < 0) {
dev_err(bus->dev, "Bank switch failed: %d", ret);return ret;- }
- /* Post-bank switch */
- if (ops->post_bank_switch) {
ret = ops->post_bank_switch(bus);if (ret < 0) {dev_err(bus->dev,
- list_for_each_entry(m_rt, &stream->master_list, stream_node) {
bus = m_rt->bus;ops = bus->ops;if (ops->post_bank_switch) {ret = ops->post_bank_switch(bus);if (ret < 0) {dev_err(bus->dev, "Post bank switch op failed: %d", ret);}};
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