lkml.org 
[lkml]   [2024]   [Apr]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH net v2 3/3] net: bcmgenet: synchronize UMAC_CMD access
From
On 4/25/24 15:27, Doug Berger wrote:
> The UMAC_CMD register is written from different execution
> contexts and has insufficient synchronization protections to
> prevent possible corruption. Of particular concern are the
> acceses from the phy_device delayed work context used by the
> adjust_link call and the BH context that may be used by the
> ndo_set_rx_mode call.
>
> A spinlock is added to the driver to protect contended register
> accesses (i.e. reg_lock) and it is used to synchronize accesses
> to UMAC_CMD.
>
> Fixes: 1c1008c793fa ("net: bcmgenet: add main driver file")
> Cc: stable@vger.kernel.org
> Signed-off-by: Doug Berger <opendmb@gmail.com>

Acked-by: Florian Fainelli <florian.fainelli@broadcom.com>

As a bug fix this is totally fine. I believe there could be an
improvement made in 'net-next' whereby we introduce an
unimac_rmw_locked() or something that essentially does:

void unimac_rmw_locked(struct bcmgenet_priv *priv, u32 offset, u32
mask_clear, u32 mask_set)
{
u32 reg;
spin_lock_bh(&priv->reg_lock);
reg = bcmgenet_umac_readl(priv, offset);
reg &= ~mask_clear;
reg |= mask_set;
bcmgenet_umac_writel(priv, reg, offset);
spin_unlock_bh(&priv->reg_lock);
}

At least a couple of callers could benefit from it. Thanks!
--
Florian

[unhandled content-type:application/pkcs7-signature]
\
 
 \ /
  Last update: 2024-05-27 18:05    [W:0.141 / U:0.680 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site