Thread (47 messages) 47 messages, 3 authors, 2020-08-06

Re: [PATCH v8 08/10] gpu: host1x: mipi: Keep MIPI clock enabled till calibration is done

From: Sowjanya Komatineni <skomatineni@nvidia.com>
Date: 2020-08-05 19:20:56
Also in: linux-media, linux-tegra, lkml

On 8/5/20 10:34 AM, Dmitry Osipenko wrote:
05.08.2020 20:29, Sowjanya Komatineni пишет:
...
quoted
UART_FST_MIPI_CAL is the clock used for calibration logic which is FSM
that goes thru sequence codes and when done waits for pads to be in
LP-11 to apply results.

MIPI_CLK is controller gate clock which is also need to be kept enabled
as incase if it sees LP-11 it updates registers so its recommended to
have this clock enabled.

We can cancel_calibration() in CSI only when csi/sensor stream on fails
and in which case there will be no LP-11 so we can unconditionally
disable MIPI_CLK.
There is no guarantee that the fail comes before the LP-11. For example,
some odd camera driver may have a complicated enable sequence which may
fail after enabling the hardware streaming.
MIPI_CLK to keep enable is for calibration logic to update results, but 
like I said calibration logic uses UART_FST_MIPI_CAL clock. So even in 
case if fail happens from sensor after having pads in LP-11 then, 
calibration logic will still be running but result update will not 
happen with clock disabled. But HW will not stuck as this is confirmed 
from HW designer.


Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help