| Message ID | cover.1721792309.git.quic_nguyenb@quicinc.com |
|---|---|
| Headers | show |
| Series | Allow platform drivers to update UIC command timeout | expand |
On Tue, 2024-07-23 at 20:49 -0700, Bao D. Nguyen wrote: > > External email : Please do not click links or open attachments until > you have verified the sender or the content. > The default UIC command timeout still remains 500ms. > Allow platform drivers to override the UIC command > timeout if desired. > > In a real product, the 500ms timeout value is probably good enough. > However, during the product development where there are a lot of > logging and debug messages being printed to the uart console, > interrupt starvations happen occasionally because the uart may > print long debug messages from different modules in the system. > While printing, the uart may have interrupts disabled for more > than 500ms, causing UIC command timeout. > The UIC command timeout would trigger more printing from > the UFS driver, and eventually a watchdog timeout may > occur unnecessarily. > > Add support for overriding the UIC command timeout value > with the newly created uic_cmd_timeout kernel module parameter. > Default value is 500ms. Supported values range from 500ms > to 2 seconds. > > Signed-off-by: Bao D. Nguyen <quic_nguyenb@quicinc.com> > Suggested-by: Bart Van Assche <bvanassche@acm.org> > Reviewed-by: Bart Van Assche <bvanassche@acm.org> > Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> > --- > drivers/ufs/core/ufshcd.c | 29 ++++++++++++++++++++++++----- > 1 file changed, 24 insertions(+), 5 deletions(-) > Reviewed-by: Peter Wang <peter.wang@mediatek.com>
The UIC command timeout default value remains as 500ms. Allow platform drivers to change the UIC command timeout as they wish. During product development where a lot of debug logging/printing can occur, the uart may print from different modules with interrupt disabled for more than 500ms, causing interrupt starvation and UIC command timeout as a result. The UIC command timeout may eventually cause a watchdog timeout unnecessarily. With this change, the platform drivers can set a different UIC command timeout as desired. The supported values range from 500ms to 2 seconds. v4 -> v5: - Changed the logic in the function uic_cmd_timeout_set() using param_set_uint_minmax() as suggested by Peter Wang. - Add a space in front of the module description string for better alignment. v3 -> v4: - Addressed Bart's concern about the two string to int conversions would yield different results. v2 -> v3: - Addressed Bart's comments. Renamed UIC_CMD_TIMEOUT to UIC_CMD_TIMEOUT_DEFAULT. Changed "Default.." to "Defaults..". Removed an extra line in the module description. v1 -> v2: - Created kernel module parameter namely uic_cmd_timeout as recommended by Bart. Addressed some other comments. - Un-do the change in the include/ufs/ufshcd.h file which added the uic_cmd_timeout field to the hba struct. - Removed the patch 2 in the series where the UIC command timeout value was overridden by the platform driver. Bao D. Nguyen (1): scsi: ufs: core: Support Updating UIC Command Timeout drivers/ufs/core/ufshcd.c | 29 ++++++++++++++++++++++++----- 1 file changed, 24 insertions(+), 5 deletions(-)