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Wysocki" , linux-kernel@vger.kernel.org, linux-rockchip@lists.infradead.org, Heiko Stuebner , Andy Yan , Sascha Hauer From: Marek Szyprowski In-Reply-To: <20230720032848.1306349-2-linux@roeck-us.net> Content-Transfer-Encoding: 7bit X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFtrGKsWRmVeSWpSXmKPExsWy7djPc7rfZu9KMbg1w9Si//xNRoupD5+w WTQvXs9m8f/Ra1aLy7vmsFl8evCf2eLJwjNMFnO/TGW2+Lt9E4sDp8emVZ1sHvvnrmH32Lyk 3qP/r4HH31n7WTx2fm9g99h+bR6zx+dNcgEcUVw2Kak5mWWpRfp2CVwZM6+uYSx4z1ex4N4W 1gbG79xdjJwcEgImEksa5zN2MXJxCAmsYJR4unwhlPOFUeLEpgdsEM5nRokpN04yw7T0zG5g gUgsZ5Q43v+DGcL5yCixfsI9FpAqXgE7id7tB8BsFgFVid+L25kg4oISJ2c+AYuLCqRK7Lg9 gRXEFhbIkLi07hQjiM0sIC5x68l8sHoRAXeJn18boeKTmCQe70oDsdkEDCW63naxgdicAlYS BycdZIOokZfY/nYO2EESAv85JG71XmSCONtF4s/6ZVC2sMSr41vYIWwZidOTe1ggGtoZJRb8 vs8E4UxglGh4fosRospa4s65X0ArOIBWaEqs36UPEXaU2Df7HBNIWEKAT+LGW0GII/gkJm2b zgwR5pXoaBOCqFaTmHV8HdzagxcuMU9gVJqFFCyzkLw/C8k7sxD2LmBkWcUonlpanJueWmyU l1quV5yYW1yal66XnJ+7iRGYtE7/O/5lB+PyVx/1DjEycTAeYpTgYFYS4U1P35UixJuSWFmV WpQfX1Sak1p8iFGag0VJnFfb9mSykEB6YklqdmpqQWoRTJaJg1OqgWn1p1/vBd/v3NZZfafW XL460Uhj25/J03le2U1bsedToOSTgGpvYX/uoCuO3JpPeaPNjdau3xck8eZ3TFZlWER/kfm/ eQKL9tiIFZ8N2NJ9Kmj/loC6Up0vAccSlY78yz7iwlyqlnSt4E3ODZ87R3nfeasLXu5IWemk 4xtSveDfNdWX8YYGJWL2txO9XiWLcBe13JvUHdB86fxON8ttsm4ndzuxp3522iI4iTWeU+Hy wkW81s8ruO5o8sUy32i37bZtVTc6Ipmh/zPlFuvuD5YfbJvXzIvy2TDPrXVNTujKG+eWizG+ P567uLrX7MSH35nuzPPsjp3LnxYRbOSnss70XXrh9bXvnKJeH2SLUGIpzkg01GIuKk4EAL/r UCbJAwAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrOIsWRmVeSWpSXmKPExsVy+t/xu7rfZu9KMbj8RNGi//xNRoupD5+w WTQvXs9m8f/Ra1aLy7vmsFl8evCf2eLJwjNMFnO/TGW2+Lt9E4sDp8emVZ1sHvvnrmH32Lyk 3qP/r4HH31n7WTx2fm9g99h+bR6zx+dNcgEcUXo2RfmlJakKGfnFJbZK0YYWRnqGlhZ6RiaW eobG5rFWRqZK+nY2Kak5mWWpRfp2CXoZM6+uYSx4z1ex4N4W1gbG79xdjJwcEgImEj2zG1hA bCGBpYwS718yQcRlJE5Oa2CFsIUl/lzrYuti5AKqec8o0bJoMliCV8BOonf7AbBmFgFVid+L 25kg4oISJ2c+AYuLCqRK/GrYBVYvLJAh0fNtFZjNLCAucevJfLB6EQF3iZ9fGxlBFjALTGKS uLd2EyvERZkSd/YtAxvEJmAo0fUW5ApODk4BK4mDkw6yQQwyk+ja2sUIYctLbH87h3kCo9As JHfMQrJvFpKWWUhaFjCyrGIUSS0tzk3PLTbUK07MLS7NS9dLzs/dxAiM0W3Hfm7ewTjv1Ue9 Q4xMHIyHGCU4mJVEeNPTd6UI8aYkVlalFuXHF5XmpBYfYjQFBsZEZinR5HxgksgriTc0MzA1 NDGzNDC1NDNWEuf1LOhIFBJITyxJzU5NLUgtgulj4uCUamDi1P33yPW7bFp5/0mun42m7rox VUsSQpa/vZJTkx3n2t6z8cSu2xum/vo5+6y67PvXvIfrZ7xmLMxg6phf155y7/OaRLY3k1aL HH38aushntbX5UY/I3W6/z5Q/TjnwbUF4edn2qWe8hPQvDTby/7O9dmrTBvVZ39y1itvFupX cTdqCdm/xiwoRnFmephkZMiUpov+3ArTPK+/zp6z4rA/Wzl/9wK1wyeO8fudqq5MUuFeseXo HevZhbbXvXeev6/6TEx6a0zv+2zr1taK0BV2QbE+h6QsZ94pEv4tWXRnu3buDCPvmbKS280/ /j793F1//uJd2ntfrbrifldhOeOeC7+aBISX77qafXf9vPatSizFGYmGWsxFxYkAVrBfb1oD AAA= X-CMS-MailID: 20230721145342eucas1p12e658a54d36d985b2811e2c21f7810ee X-Msg-Generator: CA Content-Type: text/plain; charset="utf-8" X-RootMTR: 20230721145342eucas1p12e658a54d36d985b2811e2c21f7810ee X-EPHeader: CA CMS-TYPE: 201P X-CMS-RootMailID: 20230721145342eucas1p12e658a54d36d985b2811e2c21f7810ee References: <20230720032848.1306349-1-linux@roeck-us.net> <20230720032848.1306349-2-linux@roeck-us.net> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 20.07.2023 05:28, Guenter Roeck wrote: > REGCACHE_RBTREE and REGCACHE_MAPLE dynamically allocate memory for regmap > operations. This is incompatible with spinlock based locking which is used > for fast_io operations. Reject affected configurations. > > Signed-off-by: Guenter Roeck > --- > This seems prudent, given that accesses will be protected by spinlock > but may allocate memory with GFP_KERNEL. Another option might be to use > WARN_ON instead of rejecting the configuration to avoid hard regressions > (and I think both drivers/net/ieee802154/mcr20a.c and > sound/soc/codecs/sti-sas.c may be affected, though I can not test it). This patch, which landed in today's linux-next, breaks operation of the RockChip's VOP2 DRM driver (drivers/gpu/drm/rockchip/rockchip_drm_vop2.c). I'm not sure what is the proper fix in this case. Should one change the cache type to REGCACHE_FLAT? > drivers/base/regmap/regmap.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c > index 89a7f1c459c1..b4640285c0b9 100644 > --- a/drivers/base/regmap/regmap.c > +++ b/drivers/base/regmap/regmap.c > @@ -777,6 +777,15 @@ struct regmap *__regmap_init(struct device *dev, > } else { > if ((bus && bus->fast_io) || > config->fast_io) { > + /* > + * fast_io is incompatible with REGCACHE_RBTREE and REGCACHE_MAPLE > + * since both need to dynamically allocate memory. > + */ > + if (config->cache_type == REGCACHE_RBTREE || > + config->cache_type == REGCACHE_MAPLE) { > + ret = -EINVAL; > + goto err_name; > + } > if (config->use_raw_spinlock) { > raw_spin_lock_init(&map->raw_spinlock); > map->lock = regmap_lock_raw_spinlock; Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland