| Message ID | 20210601102421.26581-2-cristian.marussi@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Review/Extend SCMI Transport Core layer | expand |
On Tue, Jun 01, 2021 at 11:24:17AM +0100, Cristian Marussi wrote: > During an async commands execution the rx buffer len is at first set to > max_msg_sz when the synchronous part of the command is first sent; once > the synchronous part completes the transport layer waits for the delayed > response which will be processed using the same xfer descriptor initially > allocated, but synchronous response received at the end of the xfer will > have shrunk the rx buffer len to the effective payload response length. > > Raise the rx buffer length again to max_msg_sz while waiting for the > delayed response, while adding an informational error message. > > Fixes: 58ecdf03dbb9 ("firmware: arm_scmi: Add support for asynchronous commands and delayed response") > Signed-off-by: Cristian Marussi <cristian.marussi@arm.com> > --- > drivers/firmware/arm_scmi/driver.c | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > > diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c > index 66eb3f0e5daf..75141b90ae53 100644 > --- a/drivers/firmware/arm_scmi/driver.c > +++ b/drivers/firmware/arm_scmi/driver.c > @@ -513,8 +513,16 @@ static int do_xfer_with_response(const struct scmi_protocol_handle *ph, > xfer->async_done = &async_response; > > ret = do_xfer(ph, xfer); > - if (!ret && !wait_for_completion_timeout(xfer->async_done, timeout)) > - ret = -ETIMEDOUT; > + if (!ret) { > + /* rx.len would have been shrunk in the sync do_xfer above */ > + reset_rx_to_maxsz(ph, xfer); Won't this race with delayed response notification ? I think so, let me know if not and how. Can't we have this before we fetch the response into xfer ?
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index 66eb3f0e5daf..75141b90ae53 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -513,8 +513,16 @@ static int do_xfer_with_response(const struct scmi_protocol_handle *ph, xfer->async_done = &async_response; ret = do_xfer(ph, xfer); - if (!ret && !wait_for_completion_timeout(xfer->async_done, timeout)) - ret = -ETIMEDOUT; + if (!ret) { + /* rx.len would have been shrunk in the sync do_xfer above */ + reset_rx_to_maxsz(ph, xfer); + if (!wait_for_completion_timeout(xfer->async_done, timeout)) { + dev_err(ph->dev, + "timed out in delayed resp(caller: %pS)\n", + (void *)_RET_IP_); + ret = -ETIMEDOUT; + } + } xfer->async_done = NULL; return ret;
During an async commands execution the rx buffer len is at first set to max_msg_sz when the synchronous part of the command is first sent; once the synchronous part completes the transport layer waits for the delayed response which will be processed using the same xfer descriptor initially allocated, but synchronous response received at the end of the xfer will have shrunk the rx buffer len to the effective payload response length. Raise the rx buffer length again to max_msg_sz while waiting for the delayed response, while adding an informational error message. Fixes: 58ecdf03dbb9 ("firmware: arm_scmi: Add support for asynchronous commands and delayed response") Signed-off-by: Cristian Marussi <cristian.marussi@arm.com> --- drivers/firmware/arm_scmi/driver.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)