Re: [PATCH v3 26/26] media: dvb-frontends: tda10048: Make the range of z explicit.
From: Mauro Carvalho Chehab <mchehab@kernel.org>
Date: 2024-05-03 10:28:14
Also in:
linux-arm-msm, linux-media, linux-mediatek, linux-staging, linux-sunxi, linux-tegra, lkml
Em Mon, 29 Apr 2024 15:05:05 +0000 Ricardo Ribalda [off-list ref] escreveu:
quoted hunk ↗ jump to hunk
We do not expect the sample_freq to be over 613MHz. Found by cocci: drivers/media/dvb-frontends/tda10048.c:345:1-7: WARNING: do_div() does a 64-by-32 division, please consider using div64_u64 instead. Signed-off-by: Ricardo Ribalda <redacted> --- drivers/media/dvb-frontends/tda10048.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)diff --git a/drivers/media/dvb-frontends/tda10048.c b/drivers/media/dvb-frontends/tda10048.c index 3e725cdcc66b..1886f733dbbf 100644 --- a/drivers/media/dvb-frontends/tda10048.c +++ b/drivers/media/dvb-frontends/tda10048.c@@ -328,7 +328,8 @@ static int tda10048_set_wref(struct dvb_frontend *fe, u32 sample_freq_hz, u32 bw) { struct tda10048_state *state = fe->demodulator_priv; - u64 t, z; + u32 z; + u64 t; dprintk(1, "%s()\n", __func__);@@ -341,6 +342,7 @@ static int tda10048_set_wref(struct dvb_frontend *fe, u32 sample_freq_hz, /* t *= 2147483648 on 32bit platforms */ t *= (2048 * 1024); t *= 1024; + /* Sample frequency is under 613MHz */
Are you sure about that? Some DVB devices have very high frequency clocks, specially if they're also used for satellite, so I can't be sure by just looking at the driver's code. Also, we had already a bunch of regressions with "fixes" like this that actually broke frontend drivers. If you're sure, please add a note at the description mentioning on what part of the datasheet you got it. Otherwise, let's stick with the current code and address cocci warning on a different way. Regards, Mauro PS.: I partially applied this patch series. I left a few patches out of the merge to let other people review/comment (and/or for me to take a deeper look later on). Regards, Mauro _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel