From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751253AbcF2Ebq (ORCPT ); Wed, 29 Jun 2016 00:31:46 -0400 Received: from mail-io0-f173.google.com ([209.85.223.173]:32847 "EHLO mail-io0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750802AbcF2Ebo (ORCPT ); Wed, 29 Jun 2016 00:31:44 -0400 MIME-Version: 1.0 In-Reply-To: References: <1464861445-11086-1-git-send-email-jitao.shi@mediatek.com> <1464861445-11086-2-git-send-email-jitao.shi@mediatek.com> From: Daniel Kurtz Date: Wed, 29 Jun 2016 12:31:23 +0800 X-Google-Sender-Auth: XOvmvgI2sJ8NgynaOha4fmf8_Hs Message-ID: Subject: Re: [PATCH 2/2 v16] drm/bridge: Add I2C based driver for ps8640 bridge To: Emil Velikov Cc: Jitao Shi , Mark Rutland , stonea168@163.com, ML dri-devel , Ajay Kumar , Vincent Palatin , cawa cheng , Yingjoe Chen , Thierry Reding , devicetree , Pawel Moll , Ian Campbell , Rob Herring , "moderated list:ARM/Mediatek SoC support" , Russell King , Matthias Brugger , =?UTF-8?B?RWRkaWUgSHVhbmcgKOm7g+aZuuWCkSk=?= , LAKML , Rahul Sharma , srv_heupstream , "Linux-Kernel@Vger. Kernel. Org" , Sascha Hauer , Kumar Gala , Andy Yan Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Emil, One answer inline below. The rest I leave to Jitao... [snip...] On Fri, Jun 17, 2016 at 3:14 AM, Emil Velikov wrote: >> +static ssize_t ps8640_update_fw_store(struct device *dev, >> + struct device_attribute *attr, >> + const char *buf, size_t count) >> +{ >> + struct i2c_client *client = to_i2c_client(dev); >> + struct ps8640 *ps_bridge = i2c_get_clientdata(client); >> + const struct firmware *fw; >> + int error; >> + >> + error = request_firmware(&fw, PS_FW_NAME, dev); > Can the device operate without a firmware ? If not, why is the > firmware loaded so later/after user interaction (via sysfs) ? I don't > recall any other driver in DRM to use such an approach. The PS8640 has internal flash, so it should always already have a working firmware. This sysfs interface is useful for user space initiated field firmware updates. Regards, -Daniel > Regards, > Emil > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Kurtz Subject: Re: [PATCH 2/2 v16] drm/bridge: Add I2C based driver for ps8640 bridge Date: Wed, 29 Jun 2016 12:31:23 +0800 Message-ID: References: <1464861445-11086-1-git-send-email-jitao.shi@mediatek.com> <1464861445-11086-2-git-send-email-jitao.shi@mediatek.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Emil Velikov Cc: Mark Rutland , stonea168@163.com, ML dri-devel , Ajay Kumar , Vincent Palatin , cawa cheng , Yingjoe Chen , Thierry Reding , devicetree , Jitao Shi , Pawel Moll , Ian Campbell , Rob Herring , "moderated list:ARM/Mediatek SoC support" , Russell King , Matthias Brugger , =?UTF-8?B?RWRkaWUgSHVhbmcgKOm7g+aZuuWCkSk=?= , LAKML , Rahul Sharma , srv_heupstream , Linux-Kernel@Vger List-Id: devicetree@vger.kernel.org SGkgRW1pbCwKCk9uZSBhbnN3ZXIgaW5saW5lIGJlbG93LiAgVGhlIHJlc3QgSSBsZWF2ZSB0byBK aXRhby4uLgoKW3NuaXAuLi5dCgpPbiBGcmksIEp1biAxNywgMjAxNiBhdCAzOjE0IEFNLCBFbWls IFZlbGlrb3YgPGVtaWwubC52ZWxpa292QGdtYWlsLmNvbT4gd3JvdGU6Cgo+PiArc3RhdGljIHNz aXplX3QgcHM4NjQwX3VwZGF0ZV9md19zdG9yZShzdHJ1Y3QgZGV2aWNlICpkZXYsCj4+ICsgICAg ICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgc3RydWN0IGRldmljZV9hdHRyaWJ1dGUg KmF0dHIsCj4+ICsgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgY29uc3QgY2hh ciAqYnVmLCBzaXplX3QgY291bnQpCj4+ICt7Cj4+ICsgICAgICAgc3RydWN0IGkyY19jbGllbnQg KmNsaWVudCA9IHRvX2kyY19jbGllbnQoZGV2KTsKPj4gKyAgICAgICBzdHJ1Y3QgcHM4NjQwICpw c19icmlkZ2UgPSBpMmNfZ2V0X2NsaWVudGRhdGEoY2xpZW50KTsKPj4gKyAgICAgICBjb25zdCBz dHJ1Y3QgZmlybXdhcmUgKmZ3Owo+PiArICAgICAgIGludCBlcnJvcjsKPj4gKwo+PiArICAgICAg IGVycm9yID0gcmVxdWVzdF9maXJtd2FyZSgmZncsIFBTX0ZXX05BTUUsIGRldik7Cj4gQ2FuIHRo ZSBkZXZpY2Ugb3BlcmF0ZSB3aXRob3V0IGEgZmlybXdhcmUgPyBJZiBub3QsIHdoeSBpcyB0aGUK PiBmaXJtd2FyZSBsb2FkZWQgc28gbGF0ZXIvYWZ0ZXIgdXNlciBpbnRlcmFjdGlvbiAodmlhIHN5 c2ZzKSA/IEkgZG9uJ3QKPiByZWNhbGwgYW55IG90aGVyIGRyaXZlciBpbiBEUk0gdG8gdXNlIHN1 Y2ggYW4gYXBwcm9hY2guCgpUaGUgUFM4NjQwIGhhcyBpbnRlcm5hbCBmbGFzaCwgc28gaXQgc2hv dWxkIGFsd2F5cyBhbHJlYWR5IGhhdmUgYQp3b3JraW5nIGZpcm13YXJlLgpUaGlzIHN5c2ZzIGlu dGVyZmFjZSBpcyB1c2VmdWwgZm9yIHVzZXIgc3BhY2UgaW5pdGlhdGVkIGZpZWxkIGZpcm13YXJl IHVwZGF0ZXMuCgpSZWdhcmRzLAotRGFuaWVsCgo+IFJlZ2FyZHMsCj4gRW1pbAo+IF9fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fCj4gZHJpLWRldmVsIG1haWxp bmcgbGlzdAo+IGRyaS1kZXZlbEBsaXN0cy5mcmVlZGVza3RvcC5vcmcKPiBodHRwczovL2xpc3Rz LmZyZWVkZXNrdG9wLm9yZy9tYWlsbWFuL2xpc3RpbmZvL2RyaS1kZXZlbApfX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fXwpkcmktZGV2ZWwgbWFpbGluZyBsaXN0 CmRyaS1kZXZlbEBsaXN0cy5mcmVlZGVza3RvcC5vcmcKaHR0cHM6Ly9saXN0cy5mcmVlZGVza3Rv cC5vcmcvbWFpbG1hbi9saXN0aW5mby9kcmktZGV2ZWwK From mboxrd@z Thu Jan 1 00:00:00 1970 From: djkurtz@chromium.org (Daniel Kurtz) Date: Wed, 29 Jun 2016 12:31:23 +0800 Subject: [PATCH 2/2 v16] drm/bridge: Add I2C based driver for ps8640 bridge In-Reply-To: References: <1464861445-11086-1-git-send-email-jitao.shi@mediatek.com> <1464861445-11086-2-git-send-email-jitao.shi@mediatek.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Emil, One answer inline below. The rest I leave to Jitao... [snip...] On Fri, Jun 17, 2016 at 3:14 AM, Emil Velikov wrote: >> +static ssize_t ps8640_update_fw_store(struct device *dev, >> + struct device_attribute *attr, >> + const char *buf, size_t count) >> +{ >> + struct i2c_client *client = to_i2c_client(dev); >> + struct ps8640 *ps_bridge = i2c_get_clientdata(client); >> + const struct firmware *fw; >> + int error; >> + >> + error = request_firmware(&fw, PS_FW_NAME, dev); > Can the device operate without a firmware ? If not, why is the > firmware loaded so later/after user interaction (via sysfs) ? I don't > recall any other driver in DRM to use such an approach. The PS8640 has internal flash, so it should always already have a working firmware. This sysfs interface is useful for user space initiated field firmware updates. Regards, -Daniel > Regards, > Emil > _______________________________________________ > dri-devel mailing list > dri-devel at lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel