diff mbox series

[net-next,v2] net: phy: correctly check soft_reset ret ONLY if defined for PHY

Message ID 20231121135332.1455-1-ansuelsmth@gmail.com (mailing list archive)
State Accepted
Commit aadbd27f9674d7f5457331fe0248b370d5c1f25d
Delegated to: Netdev Maintainers
Headers show
Series [net-next,v2] net: phy: correctly check soft_reset ret ONLY if defined for PHY | expand

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Context Check Description
netdev/series_format success Single patches do not need cover letters
netdev/codegen success Generated files up to date
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1127 this patch: 1127
netdev/cc_maintainers success CCed 7 of 7 maintainers
netdev/build_clang success Errors and warnings before: 1154 this patch: 1154
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 1154 this patch: 1154
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 18 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Christian Marangi Nov. 21, 2023, 1:53 p.m. UTC
Introduced by commit 6e2d85ec0559 ("net: phy: Stop with excessive soft
reset").

soft_reset call for phy_init_hw had multiple revision across the years
and the implementation goes back to 2014. Originally was a simple call
to write the generic PHY reset BIT, it was then moved to a dedicated
function. It was then added the option for PHY driver to define their
own special way to reset the PHY. Till this change, checking for ret was
correct as it was always filled by either the generic reset or the
custom implementation. This changed tho with commit 6e2d85ec0559 ("net:
phy: Stop with excessive soft reset"), as the generic reset call to PHY
was dropped but the ret check was never made entirely optional and
dependent whether soft_reset was defined for the PHY driver or not.

Luckly nothing was ever added before the soft_reset call so the ret
check (in the case where a PHY didn't had soft_reset defined) although
wrong, never caused problems as ret was init 0 at the start of
phy_init_hw.

To prevent any kind of problem and to make the function cleaner and more
robust, correctly move the ret check if the soft_reset section making it
optional and needed only with the function defined.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Larysa Zaremba <larysa.zaremba@intel.com>
---
Changes v2:
- Drop Fixes Tag
- Add Reviewed-by Tag
- Add Introduced by at the top of the commit description

 drivers/net/phy/phy_device.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

Comments

Simon Horman Nov. 23, 2023, 12:50 p.m. UTC | #1
On Tue, Nov 21, 2023 at 02:53:32PM +0100, Christian Marangi wrote:
> Introduced by commit 6e2d85ec0559 ("net: phy: Stop with excessive soft
> reset").
> 
> soft_reset call for phy_init_hw had multiple revision across the years
> and the implementation goes back to 2014. Originally was a simple call
> to write the generic PHY reset BIT, it was then moved to a dedicated
> function. It was then added the option for PHY driver to define their
> own special way to reset the PHY. Till this change, checking for ret was
> correct as it was always filled by either the generic reset or the
> custom implementation. This changed tho with commit 6e2d85ec0559 ("net:
> phy: Stop with excessive soft reset"), as the generic reset call to PHY
> was dropped but the ret check was never made entirely optional and
> dependent whether soft_reset was defined for the PHY driver or not.
> 
> Luckly nothing was ever added before the soft_reset call so the ret
> check (in the case where a PHY didn't had soft_reset defined) although
> wrong, never caused problems as ret was init 0 at the start of
> phy_init_hw.
> 
> To prevent any kind of problem and to make the function cleaner and more
> robust, correctly move the ret check if the soft_reset section making it
> optional and needed only with the function defined.
> 
> Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
> Reviewed-by: Larysa Zaremba <larysa.zaremba@intel.com>

I agree that it is good to only check for ret if it could be
indicating an error value. And I see that as a bonus we avoid
a now redundant in the case where phydev->drv->soft_reset is set,
which is nice.

FWIIW, in an ideal world, I think that ret would not be initialised to
0 at the top of the function, because it's unnecessary, and such
defensive programming is not in line with how kernel code is done.

In any case, this patch looks good to me.

Reviewed-by: Simon Horman <horms@kernel.org>
patchwork-bot+netdevbpf@kernel.org Nov. 24, 2023, 1:20 a.m. UTC | #2
Hello:

This patch was applied to netdev/net-next.git (main)
by David S. Miller <davem@davemloft.net>:

On Tue, 21 Nov 2023 14:53:32 +0100 you wrote:
> Introduced by commit 6e2d85ec0559 ("net: phy: Stop with excessive soft
> reset").
> 
> soft_reset call for phy_init_hw had multiple revision across the years
> and the implementation goes back to 2014. Originally was a simple call
> to write the generic PHY reset BIT, it was then moved to a dedicated
> function. It was then added the option for PHY driver to define their
> own special way to reset the PHY. Till this change, checking for ret was
> correct as it was always filled by either the generic reset or the
> custom implementation. This changed tho with commit 6e2d85ec0559 ("net:
> phy: Stop with excessive soft reset"), as the generic reset call to PHY
> was dropped but the ret check was never made entirely optional and
> dependent whether soft_reset was defined for the PHY driver or not.
> 
> [...]

Here is the summary with links:
  - [net-next,v2] net: phy: correctly check soft_reset ret ONLY if defined for PHY
    https://git.kernel.org/netdev/net-next/c/aadbd27f9674

You are awesome, thank you!
diff mbox series

Patch

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 2ce74593d6e4..478126f6b5bc 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -1235,14 +1235,13 @@  int phy_init_hw(struct phy_device *phydev)
 
 	if (phydev->drv->soft_reset) {
 		ret = phydev->drv->soft_reset(phydev);
+		if (ret < 0)
+			return ret;
+
 		/* see comment in genphy_soft_reset for an explanation */
-		if (!ret)
-			phydev->suspended = 0;
+		phydev->suspended = 0;
 	}
 
-	if (ret < 0)
-		return ret;
-
 	ret = phy_scan_fixups(phydev);
 	if (ret < 0)
 		return ret;