From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomi Valkeinen Date: Fri, 09 May 2014 07:38:54 +0000 Subject: Re: [PATCH 1/4] OMAPDSS: Fix DSS clock multiplier issue on 3703 and probably 3630 Message-Id: <536C860E.1000501@ti.com> MIME-Version: 1 Content-Type: multipart/mixed; boundary="pHgu2KOiCS7HbWwD4sJa6MmD8Hur9V33G" List-Id: References: <1398815562-24113-1-git-send-email-tony@atomide.com> <1398815562-24113-2-git-send-email-tony@atomide.com> In-Reply-To: <1398815562-24113-2-git-send-email-tony@atomide.com> To: linux-arm-kernel@lists.infradead.org --pHgu2KOiCS7HbWwD4sJa6MmD8Hur9V33G Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 30/04/14 02:52, Tony Lindgren wrote: > Otherwise we can get often errors like the following and the > display won't come on: >=20 > omapdss APPLY error: FIFO UNDERFLOW on gfx, disabling the overlay > omapdss APPLY error: SYNC_LOST on channel lcd, restarting > the output with video overlays disabled >=20 > There are some earlier references to this issue: >=20 > http://www.spinics.net/lists/linux-omap/msg59511.html > http://www.spinics.net/lists/linux-omap/msg59724.html Those don't sound like the same issue, but it's hard to say. What kind of clock rates do you get? Cat you paste debugfs/omapdss/clk, with and without this patch? What resolution do you have? If it's a very high resolution (say, DVI output to a monitor), it could just be an issue of not-enough-memory-bandwidth. > It seems that it's safe to set the lower values even for 3630. > If we can confirm that 3630 works with the higher values > reliably we can add further detection. >=20 > Signed-off-by: Tony Lindgren > --- > drivers/video/fbdev/omap2/dss/dss.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) >=20 > diff --git a/drivers/video/fbdev/omap2/dss/dss.c b/drivers/video/fbdev/= omap2/dss/dss.c > index d55266c..ad6561f 100644 > --- a/drivers/video/fbdev/omap2/dss/dss.c > +++ b/drivers/video/fbdev/omap2/dss/dss.c > @@ -707,9 +707,10 @@ static const struct dss_features omap34xx_dss_feat= s __initconst =3D { > .dpi_select_source =3D &dss_dpi_select_source_omap2_omap3, > }; > =20 > +/* Supposedly 3630 can use div 32 mult 2, but that needs to be recheck= ed */ > static const struct dss_features omap3630_dss_feats __initconst =3D { > - .fck_div_max =3D 32, > - .dss_fck_multiplier =3D 1, > + .fck_div_max =3D 16, > + .dss_fck_multiplier =3D 2, These values tell about the clock hardware, they are not settings that can be changed to change the clock. OMAP3630 has a fixed x2 multiplier and a divider with maximum value of 16. Tomi --pHgu2KOiCS7HbWwD4sJa6MmD8Hur9V33G Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJTbIYOAAoJEPo9qoy8lh71RJ0QAJC4W1o98J2/WqowIkoCb+j4 wCGBGi4t7SFi8RVvngVN6MADuYzcY3gP0aBWHAEXufugArSO1rfiDfqGYD5SYgPI LoR/z6hD1Ez1/JaBAChsurpTX7q118zsmTBgF9B2HGKJrw2ZM/20uR9NRRIPhYHt 7H1QykB5G7zvD2zpU6LLjs920GwP0Q661djAeXXOep2H+4TaG6xc8/Nwe/V1OreD E0y3Jk9k6MY04yvrKc0Iv9v1VySQL2Kat5GDD0c6UW9Yjx1jyX4PUnlhjIOFxdi/ TUzqXAk97y7lESObUAqLs5SOSwyxDE64o/jzq2OCROffCDgx5pixJuhouIz08/Pd BNltnwyhyvwESAWWP7qtf/EQ7DhxPsjY3t+WMJfUunl+2ptMf4OUPT7Nj5qaGgso PvKxpcB0/qRGbqiZtTOcNdD5mCsVmUenke9qLHQeisNLwiBYr71GtRqoATWCDfUz cyYizVqop1F4Z9KrB53IO/vyXdAW0Gk3ZskByNHGnwY047bGzUWWWn5t5HsFuopR HNR99HIdNGQoBPfnXNIsV7XBNfSptVxxcrzLhb0ypcomw0Fs5FRDTps/Bo67sV/p Szk0S78S8zeqIThGCrUyUDkz3ppaGvfi3/r2IsBrPfUlV060i8gcx17j6FdI6kA+ MWPyrLrlwB86yRfu4aFN =fan5 -----END PGP SIGNATURE----- --pHgu2KOiCS7HbWwD4sJa6MmD8Hur9V33G--