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bh=xeJuegA6Kp8h/k7mdDSuMR87SsPPFX9UGJrHs+seFbs=; b=cgOWgUUhLxtqoiYEw/+V8an6KEFIQ2fpvVQxwUMuWGh57tAJLvxXeVSNVI9uQDj9ChD6Zm 8FahPfYXALDT00pAuPJJRHhavkq8lxVigSjCrME4VhwHGe1oyNr2n0934sbuvDBoS9a0Df aZ5w02p9r+t3qfAyixweo0y/qSuhIQHQ/Hpw25WgvOvUhH80Y7ARkELnjz+P7zSiM7e+a9 pVUsxEekqRVt2Qv9eSDCjlJcN7qlAP4Z7TiQO9AMspKroou9luDTP0sjaXi+c5/XXzKaUI QW7vJ9NMFbGioATUb/LARmWZYDqe5qlcCFrn2WzdccY8704bIdXQTb8Px2U5IQ== Date: Wed, 30 Apr 2025 16:33:07 +0200 From: Luca Ceresoli To: Cosmin Tanislav Cc: Tomi Valkeinen , Wolfram Sang , Mauro Carvalho Chehab , Romain Gantois , Arnd Bergmann , Greg Kroah-Hartman , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org Subject: Re: [PATCH v4 3/9] i2c: atr: split up i2c_atr_get_mapping_by_addr() Message-ID: <20250430163307.528671a8@booty> In-Reply-To: <20250428102516.933571-4-demonsingur@gmail.com> References: <20250428102516.933571-1-demonsingur@gmail.com> <20250428102516.933571-4-demonsingur@gmail.com> Organization: Bootlin X-Mailer: Claws Mail 4.3.1 (GTK 3.24.43; x86_64-redhat-linux-gnu) Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-GND-State: clean X-GND-Score: -100 X-GND-Cause: gggruggvucftvghtrhhoucdtuddrgeefvddrtddtgddvieeileehucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecuifetpfffkfdpucggtfgfnhhsuhgsshgtrhhisggvnecuuegrihhlohhuthemuceftddunecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjughrpeffhffvvefukfgjfhhoofggtgfgsehtjeertdertddvnecuhfhrohhmpefnuhgtrgcuvegvrhgvshholhhiuceolhhutggrrdgtvghrvghsohhlihessghoohhtlhhinhdrtghomheqnecuggftrfgrthhtvghrnhepgeelffefgfehhfdtvdefueefieevkefggfelkeeiudetkeektedvhedukefgvddvnecuffhomhgrihhnpegsohhothhlihhnrdgtohhmnecukfhppedvrgdtvdemieejtdemvddtvddtmegvrgdtudemsggvgedumeelhegvjeemfeegfeemledufegvnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehinhgvthepvdgrtddvmeeijedtmedvtddvtdemvggrtddumegsvgegudemleehvgejmeefgeefmeeludefvgdphhgvlhhopegsohhothihpdhmrghilhhfrhhomheplhhutggrrdgtvghrvghsohhlihessghoohhtlhhinhdrtghomhdpnhgspghrtghpthhtohepuddtpdhrtghpthhtohepuggvmhhonhhsihhnghhurhesghhmrghilhdrtghomhdprhgtphhtthhopehtohhmihdrvhgrlhhkvghinhgvnhesihguvggrshhonhgsohgrrhgurdgtohhmpdhrtghpthhtohepfihsrgdorhgvnhgvs hgrshesshgrnhhgqdgvnhhgihhnvggvrhhinhhgrdgtohhmpdhrtghpthhtohepmhgthhgvhhgrsgeskhgvrhhnvghlrdhorhhgpdhrtghpthhtoheprhhomhgrihhnrdhgrghnthhoihhssegsohhothhlihhnrdgtohhmpdhrtghpthhtoheprghrnhgusegrrhhnuggsrdguvgdprhgtphhtthhopehgrhgvghhkhheslhhinhhugihfohhunhgurghtihhonhdrohhrghdprhgtphhtthhopehlihhnuhigqdhivdgtsehvghgvrhdrkhgvrhhnvghlrdhorhhg X-GND-Sasl: luca.ceresoli@bootlin.com On Mon, 28 Apr 2025 13:25:08 +0300 Cosmin Tanislav wrote: > The i2c_atr_get_mapping_by_addr() function handles three separate > usecases: finding an existing mapping, creating a new mapping, or > replacing an existing mapping if a new mapping cannot be created > because there aren't enough aliases available. > > Split up the function into three different functions handling its > individual usecases to prepare for better usage of each one. > > Signed-off-by: Cosmin Tanislav This function has become quite complex over time, so this looks like a good cleanup by itself even not counting the advantages coming with the following patches. I have only one small remark, see below. > diff --git a/drivers/i2c/i2c-atr.c b/drivers/i2c/i2c-atr.c > index 939fb95fe781..184c57c31e60 100644 > --- a/drivers/i2c/i2c-atr.c > +++ b/drivers/i2c/i2c-atr.c > @@ -239,9 +239,23 @@ static void i2c_atr_release_alias(struct i2c_atr_alias_pool *alias_pool, u16 ali > spin_unlock(&alias_pool->lock); > } > > -/* Must be called with alias_pairs_lock held */ > static struct i2c_atr_alias_pair * > -i2c_atr_get_mapping_by_addr(struct i2c_atr_chan *chan, u16 addr) > +i2c_atr_find_mapping_by_addr(struct i2c_atr_chan *chan, u16 addr) > +{ > + struct i2c_atr_alias_pair *c2a; > + > + lockdep_assert_held(&chan->alias_pairs_lock); > + > + list_for_each_entry(c2a, &chan->alias_pairs, node) { > + if (c2a->addr == addr) > + return c2a; > + } > + > + return NULL; > +} > + > +static struct i2c_atr_alias_pair * > +i2c_atr_replace_mapping_by_addr(struct i2c_atr_chan *chan, u16 addr) > { > struct i2c_atr *atr = chan->atr; > struct i2c_atr_alias_pair *c2a; > @@ -254,41 +268,57 @@ i2c_atr_get_mapping_by_addr(struct i2c_atr_chan *chan, u16 addr) > > alias_pairs = &chan->alias_pairs; > > - list_for_each_entry(c2a, alias_pairs, node) { > - if (c2a->addr == addr) > - return c2a; > + if (unlikely(list_empty(alias_pairs))) > + return NULL; > + > + list_for_each_entry_reverse(c2a, alias_pairs, node) { > + if (!c2a->fixed) { > + found = true; > + break; > + } > } > > + if (!found) > + return NULL; > + > + atr->ops->detach_addr(atr, chan->chan_id, c2a->addr); > + c2a->addr = addr; > + > + list_move(&c2a->node, alias_pairs); > + > + alias = c2a->alias; > + > + ret = atr->ops->attach_addr(atr, chan->chan_id, c2a->addr, c2a->alias); > + if (ret) { > + dev_err(atr->dev, "failed to attach 0x%02x on channel %d: err %d\n", > + addr, chan->chan_id, ret); > + i2c_atr_destroy_c2a(&c2a); > + i2c_atr_release_alias(chan->alias_pool, alias); > + return NULL; > + } > + > + return c2a; > +} > + > +static struct i2c_atr_alias_pair * > +i2c_atr_create_mapping_by_addr(struct i2c_atr_chan *chan, u16 addr) I would move the _create function before the _replace one, because that's the logical order in which they are called. As a nice side effect, this might make the diff more readable. Luca -- Luca Ceresoli, Bootlin Embedded Linux and Kernel engineering https://bootlin.com