Hello, On Mon, Apr 28, 2025 at 01:53:44AM +0000, Ping-Ke Shih wrote: > Ondřej Jirman <megi@xxxxxx> wrote: > > > > Internally wiphy writes to individual channels in this structure, > > so we must not share one static definition of channel list between > > multiple device instances, because that causes hard to debug > > breakage. > > > > For example, with two rtw89 driven devices in the system, channel > > information may get incoherent, preventing channel use. > > > > Signed-off-by: Ondrej Jirman <megi@xxxxxx> > > --- > > > > This patch relates to this report of mine: > > > > > > https://lore.kernel.org/linux-wireless/2goskmst4na36v42p2bs47uernp6kh3gzpadhr3u3r2yvyoxlg@bfprgq2qae7p > > /T/#u > > > > drivers/net/wireless/realtek/rtw89/core.c | 48 ++++++++++++++++++----- > > 1 file changed, 38 insertions(+), 10 deletions(-) > > > > diff --git a/drivers/net/wireless/realtek/rtw89/core.c b/drivers/net/wireless/realtek/rtw89/core.c > > index cc9b014457ac..ae22954f5f5c 100644 > > --- a/drivers/net/wireless/realtek/rtw89/core.c > > +++ b/drivers/net/wireless/realtek/rtw89/core.c > > @@ -4398,16 +4398,44 @@ static void rtw89_init_he_eht_cap(struct rtw89_dev *rtwdev, > > _ieee80211_set_sband_iftype_data(sband, iftype_data, idx); > > } > > > > +static struct ieee80211_supported_band *rtw89_copy_sband(const struct ieee80211_supported_band *sband) > > prefer naming rtw89_core_sband_dup(). > > > +{ > > + struct ieee80211_supported_band *copy = kmemdup(sband, sizeof(*sband), GFP_KERNEL); > > Then, '*dup'. > > > + > > + copy->channels = kmemdup(sband->channels, sizeof(struct ieee80211_channel) * sband->n_channels, > > GFP_KERNEL); > > I'm planning to use devm_ series to manage sband data, so we don't need to > free them one by one. Do you interest to adjust that along with this patchset? > I mean adding additional patches to adjust the code before this patch, and > make them as a patchset. Yes. > For kmemdup, the corresponding one is devm_kmemdup. > > The line is too long. Less than 80 characters is preferred. > > > + if (!copy->channels) { > > + kfree(copy); > > + return NULL; > > + } > > + > > + copy->bitrates = kmemdup(sband->bitrates, sizeof(struct ieee80211_rate) * sband->n_bitrates, > > GFP_KERNEL); > > Since you have duplicated arrays of channels and bitrate, we should add const > to them, like: > > static const struct ieee80211_channel rtw89_channels_{2ghz,5ghz,6ghz}[] > static const struct ieee80211_rate rtw89_bitrates[] That will produce: initialization discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers] warnings, because struct ieee80211_supported_band doesn't have these fields as const. The discarding of const qualifiers is apparently safe in this case, so I can either cast the pointers to non-const when assigned here: 270 static const struct ieee80211_supported_band rtw89_sband_2ghz = { 271 .band = NL80211_BAND_2GHZ, 272 .channels = rtw89_channels_2ghz, 273 .n_channels = ARRAY_SIZE(rtw89_channels_2ghz), 274 .bitrates = rtw89_bitrates, 275 .n_bitrates = ARRAY_SIZE(rtw89_bitrates), 276 .ht_cap = {0}, 277 .vht_cap = {0}, 278 }; Or the code would have to get quite a bit less readable in rtw89_core_set_supported_band() to duplicate and assign copies of bitrates and channels there for each supported band individually instead of relying on a common implementation in rtw89_core_sband_dup() function, and remove assignments from const ieee80211_supported_band definitions. Do you have a preference? kind regards, o. > > > + if (!copy->bitrates) { > > + kfree(copy->channels); > > + kfree(copy); > > + return NULL; > > + } > > + > > + return copy; > > +} > > + > > +static void rtw89_free_sband(const struct ieee80211_supported_band *sband) > > +{ > > + if (sband) { > > + kfree(sband->bitrates); > > + kfree(sband->channels); > > + kfree(sband); > > + } > > +} > > + > > static int rtw89_core_set_supported_band(struct rtw89_dev *rtwdev) > > { > > struct ieee80211_hw *hw = rtwdev->hw; > > struct ieee80211_supported_band *sband_2ghz = NULL, *sband_5ghz = NULL; > > struct ieee80211_supported_band *sband_6ghz = NULL; > > - u32 size = sizeof(struct ieee80211_supported_band); > > u8 support_bands = rtwdev->chip->support_bands; > > > > if (support_bands & BIT(NL80211_BAND_2GHZ)) { > > - sband_2ghz = kmemdup(&rtw89_sband_2ghz, size, GFP_KERNEL); > > + sband_2ghz = rtw89_copy_sband(&rtw89_sband_2ghz); > > if (!sband_2ghz) > > goto err; > > rtw89_init_ht_cap(rtwdev, &sband_2ghz->ht_cap); > > @@ -4416,7 +4444,7 @@ static int rtw89_core_set_supported_band(struct rtw89_dev *rtwdev) > > } > > > > if (support_bands & BIT(NL80211_BAND_5GHZ)) { > > - sband_5ghz = kmemdup(&rtw89_sband_5ghz, size, GFP_KERNEL); > > + sband_5ghz = rtw89_copy_sband(&rtw89_sband_5ghz); > > if (!sband_5ghz) > > goto err; > > rtw89_init_ht_cap(rtwdev, &sband_5ghz->ht_cap); > > @@ -4426,7 +4454,7 @@ static int rtw89_core_set_supported_band(struct rtw89_dev *rtwdev) > > } > > > > if (support_bands & BIT(NL80211_BAND_6GHZ)) { > > - sband_6ghz = kmemdup(&rtw89_sband_6ghz, size, GFP_KERNEL); > > + sband_6ghz = rtw89_copy_sband(&rtw89_sband_6ghz); > > if (!sband_6ghz) > > goto err; > > rtw89_init_he_eht_cap(rtwdev, NL80211_BAND_6GHZ, sband_6ghz); > > @@ -4445,9 +4473,9 @@ static int rtw89_core_set_supported_band(struct rtw89_dev *rtwdev) > > kfree((__force void *)sband_5ghz->iftype_data); > > if (sband_6ghz) > > kfree((__force void *)sband_6ghz->iftype_data); > > - kfree(sband_2ghz); > > - kfree(sband_5ghz); > > - kfree(sband_6ghz); > > + rtw89_free_sband(sband_2ghz); > > + rtw89_free_sband(sband_5ghz); > > + rtw89_free_sband(sband_6ghz); > > return -ENOMEM; > > } > > > > @@ -4461,9 +4489,9 @@ static void rtw89_core_clr_supported_band(struct rtw89_dev *rtwdev) > > kfree((__force void *)hw->wiphy->bands[NL80211_BAND_5GHZ]->iftype_data); > > if (hw->wiphy->bands[NL80211_BAND_6GHZ]) > > kfree((__force void *)hw->wiphy->bands[NL80211_BAND_6GHZ]->iftype_data); > > - kfree(hw->wiphy->bands[NL80211_BAND_2GHZ]); > > - kfree(hw->wiphy->bands[NL80211_BAND_5GHZ]); > > - kfree(hw->wiphy->bands[NL80211_BAND_6GHZ]); > > + rtw89_free_sband(hw->wiphy->bands[NL80211_BAND_2GHZ]); > > + rtw89_free_sband(hw->wiphy->bands[NL80211_BAND_5GHZ]); > > + rtw89_free_sband(hw->wiphy->bands[NL80211_BAND_6GHZ]); > > hw->wiphy->bands[NL80211_BAND_2GHZ] = NULL; > > hw->wiphy->bands[NL80211_BAND_5GHZ] = NULL; > > hw->wiphy->bands[NL80211_BAND_6GHZ] = NULL; > > Like I mentioned above, with devm_ series, I suppose this function can be > removed entirely. > >
