Messages in this thread | | | Date | Mon, 16 Jan 2023 13:13:36 +0530 | Subject | Re: [PATCH net-next v2] net: ethernet: ti: am65-cpsw/cpts: Fix CPTS release action | From | Siddharth Vadapalli <> |
| |
On 16/01/23 13:00, Leon Romanovsky wrote: > On Mon, Jan 16, 2023 at 10:15:17AM +0530, Siddharth Vadapalli wrote: >> The am65_cpts_release() function is registered as a devm_action in the >> am65_cpts_create() function in am65-cpts driver. When the am65-cpsw driver >> invokes am65_cpts_create(), am65_cpts_release() is added in the set of devm >> actions associated with the am65-cpsw driver's device. >> >> In the event of probe failure or probe deferral, the platform_drv_probe() >> function invokes dev_pm_domain_detach() which powers off the CPSW and the >> CPSW's CPTS hardware, both of which share the same power domain. Since the >> am65_cpts_disable() function invoked by the am65_cpts_release() function >> attempts to reset the CPTS hardware by writing to its registers, the CPTS >> hardware is assumed to be powered on at this point. However, the hardware >> is powered off before the devm actions are executed. >> >> Fix this by getting rid of the devm action for am65_cpts_release() and >> invoking it directly on the cleanup and exit paths. >> >> Fixes: f6bd59526ca5 ("net: ethernet: ti: introduce am654 common platform time sync driver") >> Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com> >> Reviewed-by: Roger Quadros <rogerq@kernel.org> >> --- >> Changes from v1: >> 1. Fix the build issue when "CONFIG_TI_K3_AM65_CPTS" is not set. This >> error was reported by kernel test robot <lkp@intel.com> at: >> https://lore.kernel.org/r/202301142105.lt733Lt3-lkp@intel.com/ >> 2. Collect Reviewed-by tag from Roger Quadros. >> >> v1: >> https://lore.kernel.org/r/20230113104816.132815-1-s-vadapalli@ti.com/ >> >> drivers/net/ethernet/ti/am65-cpsw-nuss.c | 8 ++++++++ >> drivers/net/ethernet/ti/am65-cpts.c | 15 +++++---------- >> drivers/net/ethernet/ti/am65-cpts.h | 5 +++++ >> 3 files changed, 18 insertions(+), 10 deletions(-) >> >> diff --git a/drivers/net/ethernet/ti/am65-cpsw-nuss.c b/drivers/net/ethernet/ti/am65-cpsw-nuss.c >> index 5cac98284184..00f25d8a026b 100644 >> --- a/drivers/net/ethernet/ti/am65-cpsw-nuss.c >> +++ b/drivers/net/ethernet/ti/am65-cpsw-nuss.c >> @@ -1913,6 +1913,12 @@ static int am65_cpsw_am654_get_efuse_macid(struct device_node *of_node, >> return 0; >> } >> >> +static void am65_cpsw_cpts_cleanup(struct am65_cpsw_common *common) >> +{ >> + if (IS_ENABLED(CONFIG_TI_K3_AM65_CPTS) && common->cpts) > > Why do you have IS_ENABLED(CONFIG_TI_K3_AM65_CPTS), if > am65_cpts_release() defined as empty when CONFIG_TI_K3_AM65_CPTS not set? > > How is it possible to have common->cpts == NULL?
Thank you for reviewing the patch. I realize now that checking CONFIG_TI_K3_AM65_CPTS is unnecessary.
common->cpts remains NULL in the following cases: 1. am65_cpsw_init_cpts() returns 0 since CONFIG_TI_K3_AM65_CPTS is not enabled. 2. am65_cpsw_init_cpts() returns -ENOENT since the cpts node is not defined. 3. The call to am65_cpts_create() fails within the am65_cpsw_init_cpts() function with a return value of 0 when cpts is disabled. 4. The call to am65_cpts_create() within the am65_cpsw_init_cpts() function fails with an error.
Of the above cases, the am65_cpsw_cpts_cleanup() function would have to handle cases 1 and 3, since the probe might fail at a later point, following which the probe cleanup path will invoke the am65_cpts_cpts_cleanup() function. This function then checks for common->cpts not being NULL, so that it can invoke the am65_cpts_release() function with this pointer.
> > And why do you need special am65_cpsw_cpts_cleanup() which does nothing > except call to am65_cpts_release()? It will be more intuitive change > the latter to be exported function.
The am65_cpts_release() function expects the cpts pointer to be valid. Thus, I had added the am65_cpsw_cpts_cleanup() function to conditionally invoke the am65_cpts_release() function whenever the cpts pointer is valid. Based on your suggestion, I believe that you want me to check for the cpts pointer being valid within the am65_cpts_release() function instead, so that the am65_cpsw_cpts_cleanup() function doesn't have to be added. Please let me know if this is what you meant.
Regards, Siddharth.
| |