From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from gofer.mess.org (gofer.mess.org [88.97.38.141]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 796B8221F1C; Wed, 11 Jun 2025 20:09:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=88.97.38.141 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749672584; cv=none; b=nDTJiGVeddijU2ZMHAK+YPc4mJi8QjpERhhnKmTua/Uq2eA7R4/VbaReHSYk4r/JTqbG0oAT2GHdY8FaE9XfqgXPfkvOPaOGFOP/jLe/pBJZzKVLHH9zn1uuHgDRMRnSRu1stJ9WV6XTtmGV8DaeGKQO/ir8ynL8lPOOv7tl1EY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749672584; c=relaxed/simple; bh=95CplAYh589c94KT4OHeDw6dyXWciFWaE0dM3Q8zu4k=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=KevIeQe8rgfw3g+YOEQ9/dmHzkuUHTImutD6gl7P3XAJ1O9FPhEZ692Ua+k6bxFykCqkWawhG0hKJ0YYbN6WIVK7EvpAq7sxao1V5njOcTYvg0yytrsmd5IzDsoHOTBL64hbXEDa/GNZPr3LOVTKqPxdTEdeolAcHVTzkeGUCgU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=mess.org; spf=pass smtp.mailfrom=mess.org; dkim=pass (2048-bit key) header.d=mess.org header.i=@mess.org header.b=fBzsLyWg; arc=none smtp.client-ip=88.97.38.141 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=mess.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=mess.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=mess.org header.i=@mess.org header.b="fBzsLyWg" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=mess.org; s=2020; t=1749672575; bh=95CplAYh589c94KT4OHeDw6dyXWciFWaE0dM3Q8zu4k=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=fBzsLyWgfrKlL9tvvk7RXWndSrn28DGDmTq6rgQD7fT7+ATd797KTZHN/r0e5Mdvr 6Qjtvrj0QY1QvhCMHaaN2DHzTckqqKpgzp0X+x9l1NlhSfIgonBIUNsOoLgi6Y7p6w w6Di/AoXl5fumu2wGrbu4IRCIaUR+hW2Ty/Hl86ePA5yOFGBhmCNZc3xvTPoOTpYTJ lLwYLAJUQhCrx2COaLtEYdapXJDPucy2no2sj8Ib5r60ixtqy7WfrMQZZ+POoK9pbM LxNHq7UXYjj3QsfcEIoUXbHWV3xw9dbsBtaYAjwMUVHMz4UKkaoZKLeoFSj+pVkjTt kB7uDSPkLOr6A== Received: by gofer.mess.org (Postfix, from userid 1000) id F2C43100069; Wed, 11 Jun 2025 21:09:34 +0100 (BST) Date: Wed, 11 Jun 2025 21:09:34 +0100 From: Sean Young To: Cosmin Tanislav Cc: Mauro Carvalho Chehab , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 2/2] media: rc: ir-spi: constrain carrier frequency Message-ID: References: <20250611112348.3576093-1-demonsingur@gmail.com> <20250611112348.3576093-3-demonsingur@gmail.com> 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-Disposition: inline In-Reply-To: <20250611112348.3576093-3-demonsingur@gmail.com> On Wed, Jun 11, 2025 at 02:23:44PM +0300, Cosmin Tanislav wrote: > Carrier frequency is currently unconstrained, allowing the SPI transfer > to be allocated and filled only for it to be later rejected by the SPI > controller since the frequency is too large. > > Add a check to constrain the carrier frequency inside > ir_spi_set_tx_carrier(). > > Also, move the number of bits per pulse to a macro since it is not used > in multiple places. > > Signed-off-by: Cosmin Tanislav > --- > drivers/media/rc/ir-spi.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/media/rc/ir-spi.c b/drivers/media/rc/ir-spi.c > index 50e30e2fae22..bf731204c81e 100644 > --- a/drivers/media/rc/ir-spi.c > +++ b/drivers/media/rc/ir-spi.c > @@ -21,6 +21,7 @@ > #define IR_SPI_DRIVER_NAME "ir-spi" > > #define IR_SPI_DEFAULT_FREQUENCY 38000 > +#define IR_SPI_BITS_PER_PULSE 16 > > struct ir_spi_data { > u32 freq; > @@ -70,7 +71,7 @@ static int ir_spi_tx(struct rc_dev *dev, unsigned int *buffer, unsigned int coun > > memset(&xfer, 0, sizeof(xfer)); > > - xfer.speed_hz = idata->freq * 16; > + xfer.speed_hz = idata->freq * IR_SPI_BITS_PER_PULSE; > xfer.len = len * sizeof(*tx_buf); > xfer.tx_buf = tx_buf; > > @@ -98,6 +99,9 @@ static int ir_spi_set_tx_carrier(struct rc_dev *dev, u32 carrier) > if (!carrier) > return -EINVAL; > > + if (carrier * IR_SPI_BITS_PER_PULSE > idata->spi->max_speed_hz) > + return -EINVAL; Just a nitpick. I think carrier * IR_SPI_BITS_PER_PULSE could overflow, and then the check wouldn't work. It might be better to do: if (carrier > idata->spi->max_speed_hz / IR_SPI_BITS_PER_PULSE) However since IR_SPI_BITS_PER_PULSE is 16, which is just a shift left by 4, I don't think this can be abused in any useful way. Sean > + > idata->freq = carrier; > > return 0; > -- > 2.49.0 >